nordic-dev.net/wgpu
nordic-dev.net/wgpu
2
0
Fork 0
mirror of https://github.com/gfx-rs/wgpu.git synced 2024-11-21 22:33:49 +00:00
Code Issues Packages Projects Releases Wiki Activity

[naga hlsl-out glsl-out] Work around backend loop/switch bugs.

Browse Source 
Introduce a new module, `naga:🔙:continue_forward`, containing
shared code for rendering Naga `Continue` statements as backend
`break` statements and assignments to introduced `bool` locals.
See the module's documentation for details.

- [hlsl-out] Transform degenerate single body switches into `do-while`
  loops. Properly render `Continue` statements enclosed by
  `Switch` statements enclosed by `Loop` statements.

- [glsl-out] Transform degenerate single body switches into `do-while`
  loops.

Improve `naga xtask validate spv` error message.

Fixes #4485.
Fixes #4514.
This commit is contained in:
Imbris 2024-04-25 00:23:41 -04:00 committed by Jim Blandy
parent 667096491d
commit 6d7975eb3b
23 changed files with 1750 additions and 223 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
CHANGELOG.md
View File

@ -296,6 +296,11 @@ This release fixes the validation errors whenever a surface is used with the vul
- Fix regression on OpenGL (EGL) where non-sRGB still used sRGB [#5642](https://github.com/gfx-rs/wgpu/pull/5642)
#### Naga
- Work around shader consumers that have bugs handling `switch` statements with a single body for all cases. These are now written as `do {} while(false);` loops in hlsl-out and glsl-out. By @Imberflur in [#5654](https://github.com/gfx-rs/wgpu/pull/5654)
- In hlsl-out, defer `continue` statements in switches by setting a flag and breaking from the switch. This allows such constructs to work with FXC which does not support `continue` within a switch. By @Imberflur in [#5654](https://github.com/gfx-rs/wgpu/pull/5654)
## v0.20.0 (2024-04-28)
### Major Changes

311
naga/src/back/continue_forward.rs Normal file
View File

@ -0,0 +1,311 @@
//! Workarounds for platform bugs and limitations in switches and loops.
//!
//! In these docs, we use CamelCase links for Naga IR concepts, and ordinary
//! `code` formatting for HLSL or GLSL concepts.
//!
//! ## Avoiding `continue` within `switch`
//!
//! As described in <https://github.com/gfx-rs/wgpu/issues/4485>, the FXC HLSL
//! compiler doesn't allow `continue` statements within `switch` statements, but
//! Naga IR does. We work around this by introducing synthetic boolean local
//! variables and branches.
//!
//! Specifically:
//!
//! - We generate code for [`Continue`] statements within [`SwitchCase`]s that
//! sets an introduced `bool` local to `true` and does a `break`, jumping to
//! immediately after the generated `switch`.
//!
//! - When generating code for a [`Switch`] statement, we conservatively assume
//! it might contain such a [`Continue`] statement, so:
//!
//! - If it's the outermost such [`Switch`] within a [`Loop`], we declare the
//! `bool` local ahead of the switch, initialized to `false`. Immediately
//! after the `switch`, we check the local and do a `continue` if it's set.
//!
//! - If the [`Switch`] is nested within other [`Switch`]es, then after the
//! generated `switch`, we check the local (which we know was declared
//! before the surrounding `switch`) and do a `break` if it's set.
//!
//! - As an optimization, we only generate the check of the local if a
//! [`Continue`] statement is encountered within the [`Switch`]. This may
//! help drivers more easily identify that the `bool` is unused.
//!
//! So while we "weaken" the [`Continue`] statement by rendering it as a `break`
//! statement, we also place checks immediately at the locations to which those
//! `break` statements will jump, until we can be sure we've reached the
//! intended target of the original [`Continue`].
//!
//! In the case of nested [`Loop`] and [`Switch`] statements, there may be
//! multiple introduced `bool` locals in scope, but there's no problem knowing
//! which one to operate on. At any point, there is at most one [`Loop`]
//! statement that could be targeted by a [`Continue`] statement, so the correct
//! `bool` local to set and test is always the one introduced for the innermost
//! enclosing [`Loop`]'s outermost [`Switch`].
//!
//! # Avoiding single body `switch` statements
//!
//! As described in <https://github.com/gfx-rs/wgpu/issues/4514>, some language
//! front ends miscompile `switch` statements where all cases branch to the same
//! body. Our HLSL and GLSL backends render [`Switch`] statements with a single
//! [`SwitchCase`] as `do {} while(false);` loops.
//!
//! However, this rewriting introduces a new loop that could "capture"
//! `continue` statements in its body. To avoid doing so, we apply the
//! [`Continue`]-to-`break` transformation described above.
//!
//! [`Continue`]: crate::Statement::Continue
//! [`Loop`]: crate::Statement::Loop
//! [`Switch`]: crate::Statement::Switch
//! [`SwitchCase`]: crate::SwitchCase
use crate::proc::Namer;
use std::rc::Rc;
/// A summary of the code surrounding a statement.
enum Nesting {
/// Currently nested in at least one [`Loop`] statement.
///
/// [`Continue`] should apply to the innermost loop.
///
/// When this entry is on the top of the stack:
///
/// * When entering an inner [`Loop`] statement, push a [`Loop`][nl] state
/// onto the stack.
///
/// * When entering a nested [`Switch`] statement, push a [`Switch`][ns]
/// state onto the stack with a new variable name. Before the generated
/// `switch`, introduce a `bool` local with that name, initialized to
/// `false`.
///
/// When exiting the [`Loop`] for which this entry was pushed, pop it from
/// the stack.
///
/// [`Continue`]: crate::Statement::Continue
/// [`Loop`]: crate::Statement::Loop
/// [`Switch`]: crate::Statement::Switch
/// [ns]: Nesting::Switch
/// [nl]: Nesting::Loop
Loop,
/// Currently nested in at least one [`Switch`] that may need to forward
/// [`Continue`]s.
///
/// This includes [`Switch`]es rendered as `do {} while(false)` loops, but
/// doesn't need to include regular [`Switch`]es in backends that can
/// support `continue` within switches.
///
/// [`Continue`] should be forwarded to the innermost surrounding [`Loop`].
///
/// When this entry is on the top of the stack:
///
/// * When entering a nested [`Loop`], push a [`Loop`][nl] state onto the
/// stack.
///
/// * When entering a nested [`Switch`], push a [`Switch`][ns] state onto
/// the stack with a clone of the introduced `bool` variable's name.
///
/// * When encountering a [`Continue`] statement, render it as code to set
/// the introduced `bool` local (whose name is held in [`variable`]) to
/// `true`, and then `break`. Set [`continue_encountered`] to `true` to
/// record that the [`Switch`] contains a [`Continue`].
///
/// * When exiting this [`Switch`], pop its entry from the stack. If
/// [`continue_encountered`] is set, then we have rendered [`Continue`]
/// statements as `break` statements that jump to this point. Generate
/// code to check `variable`, and if it is `true`:
///
/// * If there is another [`Switch`][ns] left on top of the stack, set
/// its `continue_encountered` flag, and generate a `break`. (Both
/// [`Switch`][ns]es are within the same [`Loop`] and share the same
/// introduced variable, so there's no need to set another flag to
/// continue to exit the `switch`es.)
///
/// * Otherwise, `continue`.
///
/// When we exit the [`Switch`] for which this entry was pushed, pop it.
///
/// [`Continue`]: crate::Statement::Continue
/// [`Loop`]: crate::Statement::Loop
/// [`Switch`]: crate::Statement::Switch
/// [`variable`]: Nesting::Switch::variable
/// [`continue_encountered`]: Nesting::Switch::continue_encountered
/// [ns]: Nesting::Switch
/// [nl]: Nesting::Loop
Switch {
variable: Rc<String>,
/// Set if we've generated code for a [`Continue`] statement with this
/// entry on the top of the stack.
///
/// If this is still clear when we finish rendering the [`Switch`], then
/// we know we don't need to generate branch forwarding code. Omitting
/// that may make it easier for drivers to tell that the `bool` we
/// introduced ahead of the [`Switch`] is actually unused.
///
/// [`Continue`]: crate::Statement::Continue
/// [`Switch`]: crate::Statement::Switch
continue_encountered: bool,
},
}
/// A micro-IR for code a backend should generate after a [`Switch`].
///
/// [`Switch`]: crate::Statement::Switch
pub(super) enum ExitControlFlow {
None,
/// Emit `if (continue_variable) { continue; }`
Continue {
variable: Rc<String>,
},
/// Emit `if (continue_variable) { break; }`
///
/// Used after a [`Switch`] to exit from an enclosing [`Switch`].
///
/// After the enclosing switch, its associated check will consult this same
/// variable, see that it is set, and exit early.
///
/// [`Switch`]: crate::Statement::Switch
Break {
variable: Rc<String>,
},
}
/// Utility for tracking nesting of loops and switches to orchestrate forwarding
/// of continue statements inside of a switch to the enclosing loop.
///
/// See [module docs](self) for why we need this.
#[derive(Default)]
pub(super) struct ContinueCtx {
stack: Vec<Nesting>,
}
impl ContinueCtx {
/// Resets internal state.
///
/// Use this to reuse memory between writing sessions.
pub fn clear(&mut self) {
self.stack.clear();
}
/// Updates internal state to record entering a [`Loop`] statement.
///
/// [`Loop`]: crate::Statement::Loop
pub fn enter_loop(&mut self) {
self.stack.push(Nesting::Loop);
}
/// Updates internal state to record exiting a [`Loop`] statement.
///
/// [`Loop`]: crate::Statement::Loop
pub fn exit_loop(&mut self) {
if !matches!(self.stack.pop(), Some(Nesting::Loop)) {
unreachable!("ContinueCtx stack out of sync");
}
}
/// Updates internal state to record entering a [`Switch`] statement.
///
/// Return `Some(variable)` if this [`Switch`] is nested within a [`Loop`],
/// and the caller should introcue a new `bool` local variable named
/// `variable` above the `switch`, for forwarding [`Continue`] statements.
///
/// `variable` is guaranteed not to conflict with any names used by the
/// program itself.
///
/// [`Continue`]: crate::Statement::Continue
/// [`Loop`]: crate::Statement::Loop
/// [`Switch`]: crate::Statement::Switch
pub fn enter_switch(&mut self, namer: &mut Namer) -> Option<Rc<String>> {
match self.stack.last() {
// If the stack is empty, we are not in loop, so we don't need to
// forward continue statements within this `Switch`. We can leave
// the stack empty.
None => None,
Some(&Nesting::Loop { .. }) => {
let variable = Rc::new(namer.call("should_continue"));
self.stack.push(Nesting::Switch {
variable: Rc::clone(&variable),
continue_encountered: false,
});
Some(variable)
}
Some(&Nesting::Switch { ref variable, .. }) => {
self.stack.push(Nesting::Switch {
variable: Rc::clone(variable),
continue_encountered: false,
});
// We have already declared the variable before some enclosing
// `Switch`.
None
}
}
}
/// Update internal state to record leaving a [`Switch`] statement.
///
/// Return an [`ExitControlFlow`] value indicating what code should be
/// introduced after the generated `switch` to forward continues.
///
/// [`Switch`]: crate::Statement::Switch
pub fn exit_switch(&mut self) -> ExitControlFlow {
match self.stack.pop() {
// This doesn't indicate a problem: we don't start pushing entries
// for `Switch` statements unless we have an enclosing `Loop`.
None => ExitControlFlow::None,
Some(Nesting::Loop { .. }) => {
unreachable!("Unexpected loop state when exiting switch");
}
Some(Nesting::Switch {
variable,
continue_encountered: inner_continue,
}) => {
if !inner_continue {
// No `Continue` statement was encountered, so we didn't
// introduce any `break`s jumping to this point.
ExitControlFlow::None
} else if let Some(&mut Nesting::Switch {
continue_encountered: ref mut outer_continue,
..
}) = self.stack.last_mut()
{
// This is nested in another `Switch`. Propagate upwards
// that there is a continue statement present.
*outer_continue = true;
ExitControlFlow::Break { variable }
} else {
ExitControlFlow::Continue { variable }
}
}
}
}
/// Determine what to generate for a [`Continue`] statement.
///
/// If we can generate an ordinary `continue` statement, return `None`.
///
/// Otherwise, we're enclosed by a [`Switch`] that is itself enclosed by a
/// [`Loop`]. Return `Some(variable)` to indicate that the [`Continue`]
/// should be rendered as setting `variable` to `true`, and then doing a
/// `break`.
///
/// This also notes that we've encountered a [`Continue`] statement, so that
/// we can generate the right code to forward the branch following the
/// enclosing `switch`.
///
/// [`Continue`]: crate::Statement::Continue
/// [`Loop`]: crate::Statement::Loop
/// [`Switch`]: crate::Statement::Switch
pub fn continue_encountered(&mut self) -> Option<&str> {
if let Some(&mut Nesting::Switch {
ref variable,
ref mut continue_encountered,
}) = self.stack.last_mut()
{
*continue_encountered = true;
Some(variable)
} else {
None
}
}
}

136
naga/src/back/glsl/mod.rs
View File

@ -545,6 +545,11 @@ pub struct Writer<'a, W> {
named_expressions: crate::NamedExpressions,
/// Set of expressions that need to be baked to avoid unnecessary repetition in output
need_bake_expressions: back::NeedBakeExpressions,
/// Information about nesting of loops and switches.
///
/// Used for forwarding continue statements in switches that have been
/// transformed to `do {} while(false);` loops.
continue_ctx: back::continue_forward::ContinueCtx,
/// How many views to render to, if doing multiview rendering.
multiview: Option<std::num::NonZeroU32>,
/// Mapping of varying variables to their location. Needed for reflections.
@ -619,6 +624,7 @@ impl<'a, W: Write> Writer<'a, W> {
block_id: IdGenerator::default(),
named_expressions: Default::default(),
need_bake_expressions: Default::default(),
continue_ctx: back::continue_forward::ContinueCtx::default(),
varying: Default::default(),
};
@ -2082,42 +2088,94 @@ impl<'a, W: Write> Writer<'a, W> {
selector,
ref cases,
} => {
// Start the switch
write!(self.out, "{level}")?;
write!(self.out, "switch(")?;
self.write_expr(selector, ctx)?;
writeln!(self.out, ") {{")?;
// Write all cases
let l2 = level.next();
for case in cases {
match case.value {
crate::SwitchValue::I32(value) => write!(self.out, "{l2}case {value}:")?,
crate::SwitchValue::U32(value) => write!(self.out, "{l2}case {value}u:")?,
crate::SwitchValue::Default => write!(self.out, "{l2}default:")?,
// Some GLSL consumers may not handle switches with a single
// body correctly: See wgpu#4514. Write such switch statements
// as a `do {} while(false);` loop instead.
//
// Since doing so may inadvertently capture `continue`
// statements in the switch body, we must apply continue
// forwarding. See the `naga::back::continue_forward` module
// docs for details.
let one_body = cases
.iter()
.rev()
.skip(1)
.all(|case| case.fall_through && case.body.is_empty());
if one_body {
// Unlike HLSL, in GLSL `continue_ctx` only needs to know
// about [`Switch`] statements that are being rendered as
// `do-while` loops.
if let Some(variable) = self.continue_ctx.enter_switch(&mut self.namer) {
writeln!(self.out, "{level}bool {variable} = false;",)?;
};
writeln!(self.out, "{level}do {{")?;
// Note: Expressions have no side-effects so we don't need to emit selector expression.
// Body
if let Some(case) = cases.last() {
for sta in case.body.iter() {
self.write_stmt(sta, ctx, l2)?;
}
}
// End do-while
writeln!(self.out, "{level}}} while(false);")?;
// Handle any forwarded continue statements.
use back::continue_forward::ExitControlFlow;
let op = match self.continue_ctx.exit_switch() {
ExitControlFlow::None => None,
ExitControlFlow::Continue { variable } => Some(("continue", variable)),
ExitControlFlow::Break { variable } => Some(("break", variable)),
};
if let Some((control_flow, variable)) = op {
writeln!(self.out, "{level}if ({variable}) {{")?;
writeln!(self.out, "{l2}{control_flow};")?;
writeln!(self.out, "{level}}}")?;
}
} else {
// Start the switch
write!(self.out, "{level}")?;
write!(self.out, "switch(")?;
self.write_expr(selector, ctx)?;
writeln!(self.out, ") {{")?;
// Write all cases
for case in cases {
match case.value {
crate::SwitchValue::I32(value) => {
write!(self.out, "{l2}case {value}:")?
}
crate::SwitchValue::U32(value) => {
write!(self.out, "{l2}case {value}u:")?
}
crate::SwitchValue::Default => write!(self.out, "{l2}default:")?,
}
let write_block_braces = !(case.fall_through && case.body.is_empty());
if write_block_braces {
writeln!(self.out, " {{")?;
} else {
writeln!(self.out)?;
}
for sta in case.body.iter() {
self.write_stmt(sta, ctx, l2.next())?;
}
if !case.fall_through
&& case.body.last().map_or(true, |s| !s.is_terminator())
{
writeln!(self.out, "{}break;", l2.next())?;
}
if write_block_braces {
writeln!(self.out, "{l2}}}")?;
}
}
let write_block_braces = !(case.fall_through && case.body.is_empty());
if write_block_braces {
writeln!(self.out, " {{")?;
} else {
writeln!(self.out)?;
}
for sta in case.body.iter() {
self.write_stmt(sta, ctx, l2.next())?;
}
if !case.fall_through && case.body.last().map_or(true, |s| !s.is_terminator()) {
writeln!(self.out, "{}break;", l2.next())?;
}
if write_block_braces {
writeln!(self.out, "{l2}}}")?;
}
writeln!(self.out, "{level}}}")?
}
writeln!(self.out, "{level}}}")?
}
// Loops in naga IR are based on wgsl loops, glsl can emulate the behaviour by using a
// while true loop and appending the continuing block to the body resulting on:
@ -2134,6 +2192,7 @@ impl<'a, W: Write> Writer<'a, W> {
ref continuing,
break_if,
} => {
self.continue_ctx.enter_loop();
if !continuing.is_empty() || break_if.is_some() {
let gate_name = self.namer.call("loop_init");
writeln!(self.out, "{level}bool {gate_name} = true;")?;
@ -2159,7 +2218,8 @@ impl<'a, W: Write> Writer<'a, W> {
for sta in body {
self.write_stmt(sta, ctx, level.next())?;
}
writeln!(self.out, "{level}}}")?
writeln!(self.out, "{level}}}")?;
self.continue_ctx.exit_loop();
}
// Break, continue and return as written as in C
// `break;`
@ -2169,8 +2229,14 @@ impl<'a, W: Write> Writer<'a, W> {
}
// `continue;`
Statement::Continue => {
write!(self.out, "{level}")?;
writeln!(self.out, "continue;")?
// Sometimes we must render a `Continue` statement as a `break`.
// See the docs for the `back::continue_forward` module.
if let Some(variable) = self.continue_ctx.continue_encountered() {
writeln!(self.out, "{level}{variable} = true;",)?;
writeln!(self.out, "{level}break;")?
} else {
writeln!(self.out, "{level}continue;")?
}
}
// `return expr;`, `expr` is optional
Statement::Return { value } => {

1
naga/src/back/hlsl/mod.rs
View File

@ -327,6 +327,7 @@ pub struct Writer<'a, W> {
/// Set of expressions that have associated temporary variables
named_expressions: crate::NamedExpressions,
wrapped: Wrapped,
continue_ctx: back::continue_forward::ContinueCtx,
/// A reference to some part of a global variable, lowered to a series of
/// byte offset calculations.

255
naga/src/back/hlsl/writer.rs
View File

@ -104,6 +104,7 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
entry_point_io: Vec::new(),
named_expressions: crate::NamedExpressions::default(),
wrapped: super::Wrapped::default(),
continue_ctx: back::continue_forward::ContinueCtx::default(),
temp_access_chain: Vec::new(),
need_bake_expressions: Default::default(),
}
@ -122,6 +123,7 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
self.entry_point_io.clear();
self.named_expressions.clear();
self.wrapped.clear();
self.continue_ctx.clear();
self.need_bake_expressions.clear();
}
@ -1439,6 +1441,151 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
self.write_barrier(crate::Barrier::WORK_GROUP, level)
}
/// Helper method used to write switches
fn write_switch(
&mut self,
module: &Module,
func_ctx: &back::FunctionCtx<'_>,
level: back::Level,
selector: Handle<crate::Expression>,
cases: &[crate::SwitchCase],
) -> BackendResult {
// Write all cases
let indent_level_1 = level.next();
let indent_level_2 = indent_level_1.next();
// See docs of `back::continue_forward` module.
if let Some(variable) = self.continue_ctx.enter_switch(&mut self.namer) {
writeln!(self.out, "{level}bool {variable} = false;",)?;
};
// Check if there is only one body, by seeing if all except the last case are fall through
// with empty bodies. FXC doesn't handle these switches correctly, so
// we generate a `do {} while(false);` loop instead. There must be a default case, so there
// is no need to check if one of the cases would have matched.
let one_body = cases
.iter()
.rev()
.skip(1)
.all(|case| case.fall_through && case.body.is_empty());
if one_body {
// Start the do-while
writeln!(self.out, "{level}do {{")?;
// Note: Expressions have no side-effects so we don't need to emit selector expression.
// Body
if let Some(case) = cases.last() {
for sta in case.body.iter() {
self.write_stmt(module, sta, func_ctx, indent_level_1)?;
}
}
// End do-while
writeln!(self.out, "{level}}} while(false);")?;
} else {
// Start the switch
write!(self.out, "{level}")?;
write!(self.out, "switch(")?;
self.write_expr(module, selector, func_ctx)?;
writeln!(self.out, ") {{")?;
for (i, case) in cases.iter().enumerate() {
match case.value {
crate::SwitchValue::I32(value) => {
write!(self.out, "{indent_level_1}case {value}:")?
}
crate::SwitchValue::U32(value) => {
write!(self.out, "{indent_level_1}case {value}u:")?
}
crate::SwitchValue::Default => write!(self.out, "{indent_level_1}default:")?,
}
// The new block is not only stylistic, it plays a role here:
// We might end up having to write the same case body
// multiple times due to FXC not supporting fallthrough.
// Therefore, some `Expression`s written by `Statement::Emit`
// will end up having the same name (`_expr<handle_index>`).
// So we need to put each case in its own scope.
let write_block_braces = !(case.fall_through && case.body.is_empty());
if write_block_braces {
writeln!(self.out, " {{")?;
} else {
writeln!(self.out)?;
}
// Although FXC does support a series of case clauses before
// a block[^yes], it does not support fallthrough from a
// non-empty case block to the next[^no]. If this case has a
// non-empty body with a fallthrough, emulate that by
// duplicating the bodies of all the cases it would fall
// into as extensions of this case's own body. This makes
// the HLSL output potentially quadratic in the size of the
// Naga IR.
//
// [^yes]: ```hlsl
// case 1:
// case 2: do_stuff()
// ```
// [^no]: ```hlsl
// case 1: do_this();
// case 2: do_that();
// ```
if case.fall_through && !case.body.is_empty() {
let curr_len = i + 1;
let end_case_idx = curr_len
+ cases
.iter()
.skip(curr_len)
.position(|case| !case.fall_through)
.unwrap();
let indent_level_3 = indent_level_2.next();
for case in &cases[i..=end_case_idx] {
writeln!(self.out, "{indent_level_2}{{")?;
let prev_len = self.named_expressions.len();
for sta in case.body.iter() {
self.write_stmt(module, sta, func_ctx, indent_level_3)?;
}
// Clear all named expressions that were previously inserted by the statements in the block
self.named_expressions.truncate(prev_len);
writeln!(self.out, "{indent_level_2}}}")?;
}
let last_case = &cases[end_case_idx];
if last_case.body.last().map_or(true, |s| !s.is_terminator()) {
writeln!(self.out, "{indent_level_2}break;")?;
}
} else {
for sta in case.body.iter() {
self.write_stmt(module, sta, func_ctx, indent_level_2)?;
}
if !case.fall_through && case.body.last().map_or(true, |s| !s.is_terminator()) {
writeln!(self.out, "{indent_level_2}break;")?;
}
}
if write_block_braces {
writeln!(self.out, "{indent_level_1}}}")?;
}
}
writeln!(self.out, "{level}}}")?;
}
// Handle any forwarded continue statements.
use back::continue_forward::ExitControlFlow;
let op = match self.continue_ctx.exit_switch() {
ExitControlFlow::None => None,
ExitControlFlow::Continue { variable } => Some(("continue", variable)),
ExitControlFlow::Break { variable } => Some(("break", variable)),
};
if let Some((control_flow, variable)) = op {
writeln!(self.out, "{level}if ({variable}) {{")?;
writeln!(self.out, "{indent_level_1}{control_flow};")?;
writeln!(self.out, "{level}}}")?;
}
Ok(())
}
/// Helper method used to write statements
///
/// # Notes
@ -1882,6 +2029,7 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
ref continuing,
break_if,
} => {
self.continue_ctx.enter_loop();
let l2 = level.next();
if !continuing.is_empty() || break_if.is_some() {
let gate_name = self.namer.call("loop_init");
@ -1908,10 +2056,18 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
for sta in body.iter() {
self.write_stmt(module, sta, func_ctx, l2)?;
}
writeln!(self.out, "{level}}}")?
writeln!(self.out, "{level}}}")?;
self.continue_ctx.exit_loop();
}
Statement::Break => writeln!(self.out, "{level}break;")?,
Statement::Continue => writeln!(self.out, "{level}continue;")?,
Statement::Continue => {
if let Some(variable) = self.continue_ctx.continue_encountered() {
writeln!(self.out, "{level}{variable} = true;")?;
writeln!(self.out, "{level}break;")?
} else {
writeln!(self.out, "{level}continue;")?
}
}
Statement::Barrier(barrier) => {
self.write_barrier(barrier, level)?;
}
@ -2063,100 +2219,7 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
selector,
ref cases,
} => {
// Start the switch
write!(self.out, "{level}")?;
write!(self.out, "switch(")?;
self.write_expr(module, selector, func_ctx)?;
writeln!(self.out, ") {{")?;
// Write all cases
let indent_level_1 = level.next();
let indent_level_2 = indent_level_1.next();
for (i, case) in cases.iter().enumerate() {
match case.value {
crate::SwitchValue::I32(value) => {
write!(self.out, "{indent_level_1}case {value}:")?
}
crate::SwitchValue::U32(value) => {
write!(self.out, "{indent_level_1}case {value}u:")?
}
crate::SwitchValue::Default => {
write!(self.out, "{indent_level_1}default:")?
}
}
// The new block is not only stylistic, it plays a role here:
// We might end up having to write the same case body
// multiple times due to FXC not supporting fallthrough.
// Therefore, some `Expression`s written by `Statement::Emit`
// will end up having the same name (`_expr<handle_index>`).
// So we need to put each case in its own scope.
let write_block_braces = !(case.fall_through && case.body.is_empty());
if write_block_braces {
writeln!(self.out, " {{")?;
} else {
writeln!(self.out)?;
}
// Although FXC does support a series of case clauses before
// a block[^yes], it does not support fallthrough from a
// non-empty case block to the next[^no]. If this case has a
// non-empty body with a fallthrough, emulate that by
// duplicating the bodies of all the cases it would fall
// into as extensions of this case's own body. This makes
// the HLSL output potentially quadratic in the size of the
// Naga IR.
//
// [^yes]: ```hlsl
// case 1:
// case 2: do_stuff()
// ```
// [^no]: ```hlsl
// case 1: do_this();
// case 2: do_that();
// ```
if case.fall_through && !case.body.is_empty() {
let curr_len = i + 1;
let end_case_idx = curr_len
+ cases
.iter()
.skip(curr_len)
.position(|case| !case.fall_through)
.unwrap();
let indent_level_3 = indent_level_2.next();
for case in &cases[i..=end_case_idx] {
writeln!(self.out, "{indent_level_2}{{")?;
let prev_len = self.named_expressions.len();
for sta in case.body.iter() {
self.write_stmt(module, sta, func_ctx, indent_level_3)?;
}
// Clear all named expressions that were previously inserted by the statements in the block
self.named_expressions.truncate(prev_len);
writeln!(self.out, "{indent_level_2}}}")?;
}
let last_case = &cases[end_case_idx];
if last_case.body.last().map_or(true, |s| !s.is_terminator()) {
writeln!(self.out, "{indent_level_2}break;")?;
}
} else {
for sta in case.body.iter() {
self.write_stmt(module, sta, func_ctx, indent_level_2)?;
}
if !case.fall_through
&& case.body.last().map_or(true, |s| !s.is_terminator())
{
writeln!(self.out, "{indent_level_2}break;")?;
}
}
if write_block_braces {
writeln!(self.out, "{indent_level_1}}}")?;
}
}
writeln!(self.out, "{level}}}")?
self.write_switch(module, func_ctx, level, selector, cases)?;
}
Statement::RayQuery { .. } => unreachable!(),
Statement::SubgroupBallot { result, predicate } => {

3
naga/src/back/mod.rs
View File

@ -19,6 +19,9 @@ pub mod wgsl;
#[cfg(any(hlsl_out, msl_out, spv_out, glsl_out))]
pub mod pipeline_constants;
#[cfg(any(feature = "hlsl-out", feature = "glsl-out"))]
mod continue_forward;
/// Names of vector components.
pub const COMPONENTS: &[char] = &['x', 'y', 'z', 'w'];
/// Indent for backends.

93
naga/tests/in/control-flow.wgsl
View File

@ -88,3 +88,96 @@ fn loop_switch_continue(x: i32) {
}
}
}
fn loop_switch_continue_nesting(x: i32, y: i32, z: i32) {
loop {
switch x {
case 1: {
continue;
}
case 2: {
switch y {
case 1: {
continue;
}
default: {
loop {
switch z {
case 1: {
continue;
}
default: {}
}
}
}
}
}
default: {}
}
// Degenerate switch with continue
switch y {
default: {
continue;
}
}
}
// In separate loop to avoid spv validation error:
// See https://github.com/gfx-rs/wgpu/issues/5658
loop {
// Nested degenerate switch with continue
switch y {
case 1, default: {
switch z {
default: {
continue;
}
}
}
}
}
}
// Cases with some of the loop nested switches not containing continues.
// See `continue_forward` module in `naga`.
fn loop_switch_omit_continue_variable_checks(x: i32, y: i32, z: i32, w: i32) {
// switch in loop with no continues, we expect checks after the switch
// statement to not be generated
var pos: i32 = 0;
loop {
switch x {
case 1: {
pos = 1;
}
default: {}
}
// check here can be omitted
}
loop {
switch x {
case 1: {}
case 2: {
switch y {
case 1: {
continue;
}
default: {
switch z {
case 1: {
pos = 2;
}
default: {}
}
// check here can be omitted
}
}
// check needs to be generated here
}
default: {}
}
// check needs to be generated here
}
}

121
naga/tests/out/glsl/control-flow.main.Compute.glsl
View File

@ -7,11 +7,9 @@ layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
void switch_default_break(int i) {
switch(i) {
default: {
break;
}
}
do {
break;
} while(false);
}
void switch_case_break() {
@ -40,6 +38,110 @@ void loop_switch_continue(int x) {
return;
}
void loop_switch_continue_nesting(int x_1, int y, int z) {
while(true) {
switch(x_1) {
case 1: {
continue;
}
case 2: {
switch(y) {
case 1: {
continue;
}
default: {
while(true) {
switch(z) {
case 1: {
continue;
}
default: {
break;
}
}
}
break;
}
}
break;
}
default: {
break;
}
}
bool should_continue = false;
do {
should_continue = true;
break;
} while(false);
if (should_continue) {
continue;
}
}
while(true) {
bool should_continue_1 = false;
do {
do {
should_continue_1 = true;
break;
} while(false);
if (should_continue_1) {
break;
}
} while(false);
if (should_continue_1) {
continue;
}
}
return;
}
void loop_switch_omit_continue_variable_checks(int x_2, int y_1, int z_1, int w) {
int pos_1 = 0;
while(true) {
switch(x_2) {
case 1: {
pos_1 = 1;
break;
}
default: {
break;
}
}
}
while(true) {
switch(x_2) {
case 1: {
break;
}
case 2: {
switch(y_1) {
case 1: {
continue;
}
default: {
switch(z_1) {
case 1: {
pos_1 = 2;
break;
}
default: {
break;
}
}
break;
}
}
break;
}
default: {
break;
}
}
}
return;
}
void main() {
uvec3 global_id = gl_GlobalInvocationID;
int pos = 0;
@ -47,12 +149,9 @@ void main() {
barrier();
memoryBarrierShared();
barrier();
switch(1) {
default: {
pos = 1;
break;
}
}
do {
pos = 1;
} while(false);
int _e4 = pos;
switch(_e4) {
case 1: {

154
naga/tests/out/hlsl/control-flow.hlsl
View File

@ -1,10 +1,8 @@
void switch_default_break(int i)
{
switch(i) {
default: {
break;
}
}
do {
break;
} while(false);
}
void switch_case_break()
@ -23,14 +21,149 @@ void switch_case_break()
void loop_switch_continue(int x)
{
while(true) {
bool should_continue = false;
switch(x) {
case 1: {
continue;
should_continue = true;
break;
}
default: {
break;
}
}
if (should_continue) {
continue;
}
}
return;
}
void loop_switch_continue_nesting(int x_1, int y, int z)
{
while(true) {
bool should_continue_1 = false;
switch(x_1) {
case 1: {
should_continue_1 = true;
break;
}
case 2: {
switch(y) {
case 1: {
should_continue_1 = true;
break;
}
default: {
while(true) {
bool should_continue_2 = false;
switch(z) {
case 1: {
should_continue_2 = true;
break;
}
default: {
break;
}
}
if (should_continue_2) {
continue;
}
}
break;
}
}
if (should_continue_1) {
break;
}
break;
}
default: {
break;
}
}
if (should_continue_1) {
continue;
}
bool should_continue_3 = false;
do {
should_continue_3 = true;
break;
} while(false);
if (should_continue_3) {
continue;
}
}
while(true) {
bool should_continue_4 = false;
do {
do {
should_continue_4 = true;
break;
} while(false);
if (should_continue_4) {
break;
}
} while(false);
if (should_continue_4) {
continue;
}
}
return;
}
void loop_switch_omit_continue_variable_checks(int x_2, int y_1, int z_1, int w)
{
int pos_1 = 0;
while(true) {
bool should_continue_5 = false;
switch(x_2) {
case 1: {
pos_1 = 1;
break;
}
default: {
break;
}
}
}
while(true) {
bool should_continue_6 = false;
switch(x_2) {
case 1: {
break;
}
case 2: {
switch(y_1) {
case 1: {
should_continue_6 = true;
break;
}
default: {
switch(z_1) {
case 1: {
pos_1 = 2;
break;
}
default: {
break;
}
}
break;
}
}
if (should_continue_6) {
break;
}
break;
}
default: {
break;
}
}
if (should_continue_6) {
continue;
}
}
return;
}
@ -42,12 +175,9 @@ void main(uint3 global_id : SV_DispatchThreadID)
DeviceMemoryBarrierWithGroupSync();
GroupMemoryBarrierWithGroupSync();
switch(1) {
default: {
pos = 1;
break;
}
}
do {
pos = 1;
} while(false);
int _e4 = pos;
switch(_e4) {
case 1: {

108
naga/tests/out/msl/control-flow.msl
View File

@ -44,6 +44,114 @@ void loop_switch_continue(
return;
}
void loop_switch_continue_nesting(
int x_1,
int y,
int z
) {
while(true) {
switch(x_1) {
case 1: {
continue;
}
case 2: {
switch(y) {
case 1: {
continue;
}
default: {
while(true) {
switch(z) {
case 1: {
continue;
}
default: {
break;
}
}
}
break;
}
}
break;
}
default: {
break;
}
}
switch(y) {
default: {
continue;
}
}
}
while(true) {
switch(y) {
case 1:
default: {
switch(z) {
default: {
continue;
}
}
break;
}
}
}
return;
}
void loop_switch_omit_continue_variable_checks(
int x_2,
int y_1,
int z_1,
int w
) {
int pos_1 = 0;
while(true) {
switch(x_2) {
case 1: {
pos_1 = 1;
break;
}
default: {
break;
}
}
}
while(true) {
switch(x_2) {
case 1: {
break;
}
case 2: {
switch(y_1) {
case 1: {
continue;
}
default: {
switch(z_1) {
case 1: {
pos_1 = 2;
break;
}
default: {
break;
}
}
break;
}
}
break;
}
default: {
break;
}
}
}
return;
}
struct main_Input {
};
kernel void main_(

257
naga/tests/out/spv/control-flow.spvasm
View File

@ -1,13 +1,13 @@
; SPIR-V
; Version: 1.1
; Generator: rspirv
; Bound: 69
; Bound: 134
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint GLCompute %36 "main" %33
OpExecutionMode %36 LocalSize 1 1 1
OpDecorate %33 BuiltIn GlobalInvocationId
OpEntryPoint GLCompute %104 "main" %101
OpExecutionMode %104 LocalSize 1 1 1
OpDecorate %101 BuiltIn GlobalInvocationId
%2 = OpTypeVoid
%4 = OpTypeInt 32 0
%3 = OpTypeVector %4 3
@ -15,19 +15,21 @@ OpDecorate %33 BuiltIn GlobalInvocationId
%9 = OpTypeFunction %2 %5
%15 = OpTypeFunction %2
%16 = OpConstant %5 0
%34 = OpTypePointer Input %3
%33 = OpVariable %34 Input
%37 = OpConstant %5 1
%38 = OpConstant %5 2
%39 = OpConstant %5 3
%40 = OpConstant %5 4
%41 = OpConstant %4 0
%43 = OpTypePointer Function %5
%44 = OpConstantNull %5
%46 = OpConstant %4 2
%47 = OpConstant %4 1
%48 = OpConstant %4 72
%49 = OpConstant %4 264
%37 = OpTypeFunction %2 %5 %5 %5
%73 = OpTypeFunction %2 %5 %5 %5 %5
%74 = OpConstant %5 1
%75 = OpConstant %5 2
%77 = OpTypePointer Function %5
%102 = OpTypePointer Input %3
%101 = OpVariable %102 Input
%105 = OpConstant %5 3
%106 = OpConstant %5 4
%107 = OpConstant %4 0
%109 = OpConstantNull %5
%111 = OpConstant %4 2
%112 = OpConstant %4 1
%113 = OpConstant %4 72
%114 = OpConstant %4 264
%8 = OpFunction %2 None %9
%7 = OpFunctionParameter %5
%6 = OpLabel
@ -76,63 +78,198 @@ OpBranch %25
%26 = OpLabel
OpReturn
OpFunctionEnd
%36 = OpFunction %2 None %15
%36 = OpFunction %2 None %37
%33 = OpFunctionParameter %5
%34 = OpFunctionParameter %5
%35 = OpFunctionParameter %5
%32 = OpLabel
%42 = OpVariable %43 Function %44
%35 = OpLoad %3 %33
OpBranch %45
OpBranch %38
%38 = OpLabel
OpBranch %39
%39 = OpLabel
OpLoopMerge %40 %42 None
OpBranch %41
%41 = OpLabel
OpSelectionMerge %43 None
OpSwitch %33 %46 1 %44 2 %45
%44 = OpLabel
OpBranch %42
%45 = OpLabel
OpControlBarrier %46 %47 %48
OpControlBarrier %46 %46 %49
OpSelectionMerge %50 None
OpSwitch %37 %51
%51 = OpLabel
OpStore %42 %37
OpSelectionMerge %47 None
OpSwitch %34 %49 1 %48
%48 = OpLabel
OpBranch %42
%49 = OpLabel
OpBranch %50
%50 = OpLabel
%52 = OpLoad %5 %42
OpSelectionMerge %53 None
OpSwitch %52 %58 1 %54 2 %55 3 %56 4 %56 5 %57 6 %58
%54 = OpLabel
OpStore %42 %16
OpBranch %53
OpLoopMerge %51 %53 None
OpBranch %52
%52 = OpLabel
OpSelectionMerge %54 None
OpSwitch %35 %56 1 %55
%55 = OpLabel
OpStore %42 %37
OpBranch %53
%56 = OpLabel
OpStore %42 %38
OpBranch %53
%57 = OpLabel
OpStore %42 %39
OpBranch %53
%58 = OpLabel
OpStore %42 %40
OpBranch %54
%54 = OpLabel
OpBranch %53
%53 = OpLabel
OpSelectionMerge %59 None
OpSwitch %41 %61 0 %60
%60 = OpLabel
OpBranch %59
%61 = OpLabel
OpBranch %50
%51 = OpLabel
OpBranch %47
%47 = OpLabel
OpBranch %43
%46 = OpLabel
OpBranch %43
%43 = OpLabel
OpSelectionMerge %57 None
OpSwitch %34 %58
%58 = OpLabel
OpBranch %42
%57 = OpLabel
OpBranch %42
%42 = OpLabel
OpBranch %39
%40 = OpLabel
OpBranch %59
%59 = OpLabel
%62 = OpLoad %5 %42
OpLoopMerge %60 %62 None
OpBranch %61
%61 = OpLabel
OpSelectionMerge %63 None
OpSwitch %62 %68 1 %64 2 %65 3 %66 4 %67
OpSwitch %34 %64 1 %64
%64 = OpLabel
OpStore %42 %16
OpBranch %63
%65 = OpLabel
OpStore %42 %37
OpReturn
OpSelectionMerge %65 None
OpSwitch %35 %66
%66 = OpLabel
OpStore %42 %38
OpReturn
%67 = OpLabel
OpReturn
%68 = OpLabel
OpStore %42 %39
OpReturn
OpBranch %62
%65 = OpLabel
OpBranch %63
%63 = OpLabel
OpBranch %62
%62 = OpLabel
OpBranch %59
%60 = OpLabel
OpReturn
OpFunctionEnd
%72 = OpFunction %2 None %73
%68 = OpFunctionParameter %5
%69 = OpFunctionParameter %5
%70 = OpFunctionParameter %5
%71 = OpFunctionParameter %5
%67 = OpLabel
%76 = OpVariable %77 Function %16
OpBranch %78
%78 = OpLabel
OpBranch %79
%79 = OpLabel
OpLoopMerge %80 %82 None
OpBranch %81
%81 = OpLabel
OpSelectionMerge %83 None
OpSwitch %68 %85 1 %84
%84 = OpLabel
OpStore %76 %74
OpBranch %83
%85 = OpLabel
OpBranch %83
%83 = OpLabel
OpBranch %82
%82 = OpLabel
OpBranch %79
%80 = OpLabel
OpBranch %86
%86 = OpLabel
OpLoopMerge %87 %89 None
OpBranch %88
%88 = OpLabel
OpSelectionMerge %90 None
OpSwitch %68 %93 1 %91 2 %92
%91 = OpLabel
OpBranch %90
%92 = OpLabel
OpSelectionMerge %94 None
OpSwitch %69 %96 1 %95
%95 = OpLabel
OpBranch %89
%96 = OpLabel
OpSelectionMerge %97 None
OpSwitch %70 %99 1 %98
%98 = OpLabel
OpStore %76 %75
OpBranch %97
%99 = OpLabel
OpBranch %97
%97 = OpLabel
OpBranch %94
%94 = OpLabel
OpBranch %90
%93 = OpLabel
OpBranch %90
%90 = OpLabel
OpBranch %89
%89 = OpLabel
OpBranch %86
%87 = OpLabel
OpReturn
OpFunctionEnd
%104 = OpFunction %2 None %15
%100 = OpLabel
%108 = OpVariable %77 Function %109
%103 = OpLoad %3 %101
OpBranch %110
%110 = OpLabel
OpControlBarrier %111 %112 %113
OpControlBarrier %111 %111 %114
OpSelectionMerge %115 None
OpSwitch %74 %116
%116 = OpLabel
OpStore %108 %74
OpBranch %115
%115 = OpLabel
%117 = OpLoad %5 %108
OpSelectionMerge %118 None
OpSwitch %117 %123 1 %119 2 %120 3 %121 4 %121 5 %122 6 %123
%119 = OpLabel
OpStore %108 %16
OpBranch %118
%120 = OpLabel
OpStore %108 %74
OpBranch %118
%121 = OpLabel
OpStore %108 %75
OpBranch %118
%122 = OpLabel
OpStore %108 %105
OpBranch %118
%123 = OpLabel
OpStore %108 %106
OpBranch %118
%118 = OpLabel
OpSelectionMerge %124 None
OpSwitch %107 %126 0 %125
%125 = OpLabel
OpBranch %124
%126 = OpLabel
OpBranch %124
%124 = OpLabel
%127 = OpLoad %5 %108
OpSelectionMerge %128 None
OpSwitch %127 %133 1 %129 2 %130 3 %131 4 %132
%129 = OpLabel
OpStore %108 %16
OpBranch %128
%130 = OpLabel
OpStore %108 %74
OpReturn
%131 = OpLabel
OpStore %108 %75
OpReturn
%132 = OpLabel
OpReturn
%133 = OpLabel
OpStore %108 %105
OpReturn
%128 = OpLabel
OpReturn
OpFunctionEnd

86
naga/tests/out/wgsl/control-flow.wgsl
View File

@ -30,6 +30,92 @@ fn loop_switch_continue(x: i32) {
return;
}
fn loop_switch_continue_nesting(x_1: i32, y: i32, z: i32) {
loop {
switch x_1 {
case 1: {
continue;
}
case 2: {
switch y {
case 1: {
continue;
}
default: {
loop {
switch z {
case 1: {
continue;
}
default: {
}
}
}
}
}
}
default: {
}
}
switch y {
default: {
continue;
}
}
}
loop {
switch y {
case 1, default: {
switch z {
default: {
continue;
}
}
}
}
}
return;
}
fn loop_switch_omit_continue_variable_checks(x_2: i32, y_1: i32, z_1: i32, w: i32) {
var pos_1: i32 = 0i;
loop {
switch x_2 {
case 1: {
pos_1 = 1i;
}
default: {
}
}
}
loop {
switch x_2 {
case 1: {
}
case 2: {
switch y_1 {
case 1: {
continue;
}
default: {
switch z_1 {
case 1: {
pos_1 = 2i;
}
default: {
}
}
}
}
}
default: {
}
}
}
return;
}
@compute @workgroup_size(1, 1, 1)
fn main(@builtin(global_invocation_id) global_id: vec3<u32>) {
var pos: i32;

18
naga/xtask/src/validate.rs
View File

@ -208,7 +208,10 @@ fn validate_spirv(path: &Path, spirv_as: &str, spirv_val: &str) -> anyhow::Resul
buf
};
let expected_header_prefix = "; Version: ";
let Some(version) = second_line.strip_prefix(expected_header_prefix) else {
let Some(version) = second_line
.strip_prefix(expected_header_prefix)
.map(str::trim)
else {
bail!("no {expected_header_prefix:?} header found in {path:?}");
};
let file = open_file(path)?;
@ -222,7 +225,18 @@ fn validate_spirv(path: &Path, spirv_as: &str, spirv_val: &str) -> anyhow::Resul
let child = spirv_as_cmd
.spawn()
.with_context(|| format!("failed to spawn {spirv_as_cmd:?}"))?;
EasyCommand::new(spirv_val, |cmd| cmd.stdin(child.stdout.unwrap())).success()
let error_message = || {
format!(
"Failed to validate {path:?}.
Note: Labels and line numbers will not match the input file.
Use this command to view the corresponding spvasm:
'{spirv_as} --target-env spv{version} {} -o - | spirv-dis'\n",
path.display(),
)
};
EasyCommand::new(spirv_val, |cmd| cmd.stdin(child.stdout.unwrap()))
.success()
.with_context(error_message)
}
fn validate_metal(path: &Path, xcrun: &str) -> anyhow::Result<()> {

17
tests/src/init.rs
View File

@ -11,7 +11,7 @@ pub fn init_logger() {
}
/// Initialize a wgpu instance with the options from the environment.
pub fn initialize_instance() -> Instance {
pub fn initialize_instance(force_fxc: bool) -> Instance {
// We ignore `WGPU_BACKEND` for now, merely using test filtering to only run a single backend's tests.
//
// We can potentially work support back into the test runner in the future, but as the adapters are matched up
@ -27,7 +27,13 @@ pub fn initialize_instance() -> Instance {
} else {
Backends::all()
};
let dx12_shader_compiler = wgpu::util::dx12_shader_compiler_from_env().unwrap_or_default();
// Some tests need to be able to force demote to FXC, to specifically test workarounds for FXC
// behavior.
let dx12_shader_compiler = if force_fxc {
wgpu::Dx12Compiler::Fxc
} else {
wgpu::util::dx12_shader_compiler_from_env().unwrap_or_default()
};
let gles_minor_version = wgpu::util::gles_minor_version_from_env().unwrap_or_default();
Instance::new(wgpu::InstanceDescriptor {
backends,
@ -38,8 +44,11 @@ pub fn initialize_instance() -> Instance {
}
/// Initialize a wgpu adapter, taking the `n`th adapter from the instance.
pub async fn initialize_adapter(adapter_index: usize) -> (Instance, Adapter, Option<SurfaceGuard>) {
let instance = initialize_instance();
pub async fn initialize_adapter(
adapter_index: usize,
force_fxc: bool,
) -> (Instance, Adapter, Option<SurfaceGuard>) {
let instance = initialize_instance(force_fxc);
#[allow(unused_variables)]
let surface: Option<wgpu::Surface>;
let surface_guard: Option<SurfaceGuard>;

11
tests/src/params.rs
View File

@ -19,6 +19,11 @@ pub struct TestParameters {
pub required_downlevel_caps: DownlevelCapabilities,
pub required_limits: Limits,
/// On Dx12, specifically test against the Fxc compiler.
///
/// For testing workarounds to Fxc bugs.
pub force_fxc: bool,
/// Conditions under which this test should be skipped.
pub skips: Vec<FailureCase>,
@ -32,6 +37,7 @@ impl Default for TestParameters {
required_features: Features::empty(),
required_downlevel_caps: LOWEST_DOWNLEVEL_PROPERTIES,
required_limits: Limits::downlevel_webgl2_defaults(),
force_fxc: false,
skips: Vec::new(),
failures: Vec::new(),
}
@ -63,6 +69,11 @@ impl TestParameters {
self
}
pub fn force_fxc(mut self, force_fxc: bool) -> Self {
self.force_fxc = force_fxc;
self
}
/// Mark the test as always failing, but not to be skipped.
pub fn expect_fail(mut self, when: FailureCase) -> Self {
self.failures.push(when);

3
tests/src/run.rs
View File

@ -42,7 +42,8 @@ pub async fn execute_test(
let _test_guard = isolation::OneTestPerProcessGuard::new();
let (instance, adapter, _surface_guard) = initialize_adapter(adapter_index).await;
let (instance, adapter, _surface_guard) =
initialize_adapter(adapter_index, config.params.force_fxc).await;
let adapter_info = adapter.get_info();
let adapter_downlevel_capabilities = adapter.get_downlevel_capabilities();

2
tests/tests/create_surface_error.rs
View File

@ -6,7 +6,7 @@
#[wasm_bindgen_test::wasm_bindgen_test]
fn canvas_get_context_returned_null() {
// Not using the normal testing infrastructure because that goes straight to creating the canvas for us.
let instance = wgpu_test::initialize_instance();
let instance = wgpu_test::initialize_instance(false);
// Create canvas
let canvas = wgpu_test::initialize_html_canvas();

2
tests/tests/device.rs
View File

@ -107,7 +107,7 @@ static REQUEST_DEVICE_ERROR_MESSAGE_NATIVE: GpuTestConfiguration =
async fn request_device_error_message() {
// Not using initialize_test() because that doesn't let us catch the error
// nor .await anything
let (_instance, adapter, _surface_guard) = wgpu_test::initialize_adapter(0).await;
let (_instance, adapter, _surface_guard) = wgpu_test::initialize_adapter(0, false).await;
let device_error = adapter
.request_device(

106
tests/tests/regression/issue_4485.rs Normal file
View File

@ -0,0 +1,106 @@
use wgpu_test::{gpu_test, image, GpuTestConfiguration, TestParameters, TestingContext};
/// FXC doesn't accept `continue` inside a switch. Instead we store a flag for whether
/// the loop should continue that is checked after the switch.
///
/// See <https://github.com/gfx-rs/wgpu/issues/4485>.
///
/// The shader will fail to compile on Dx12 with FXC without this fix.
///
/// This also tests that shaders generated with this fix execute correctly.
#[gpu_test]
static CONTINUE_SWITCH: GpuTestConfiguration = GpuTestConfiguration::new()
.parameters(TestParameters::default().force_fxc(true))
.run_async(|ctx| async move { test_impl(&ctx).await });
async fn test_impl(ctx: &TestingContext) {
const TEXTURE_HEIGHT: u32 = 2;
const TEXTURE_WIDTH: u32 = 2;
const BUFFER_SIZE: usize = (TEXTURE_WIDTH * TEXTURE_HEIGHT * 4) as usize;
let texture = ctx.device.create_texture(&wgpu::TextureDescriptor {
label: Some("Offscreen texture"),
size: wgpu::Extent3d {
width: TEXTURE_WIDTH,
height: TEXTURE_HEIGHT,
depth_or_array_layers: 1,
},
mip_level_count: 1,
sample_count: 1,
dimension: wgpu::TextureDimension::D2,
format: wgpu::TextureFormat::Rgba8Unorm,
usage: wgpu::TextureUsages::COPY_SRC | wgpu::TextureUsages::RENDER_ATTACHMENT,
view_formats: &[],
});
let texture_view = texture.create_view(&wgpu::TextureViewDescriptor::default());
let shader = ctx
.device
.create_shader_module(wgpu::include_wgsl!("issue_4514.wgsl"));
let pipeline = ctx
.device
.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
label: Some("Pipeline"),
layout: None,
vertex: wgpu::VertexState {
module: &shader,
entry_point: "vs_main",
compilation_options: Default::default(),
buffers: &[],
},
primitive: wgpu::PrimitiveState::default(),
depth_stencil: None,
multisample: wgpu::MultisampleState::default(),
fragment: Some(wgpu::FragmentState {
module: &shader,
entry_point: "fs_main",
compilation_options: Default::default(),
targets: &[Some(wgpu::ColorTargetState {
format: wgpu::TextureFormat::Rgba8Unorm,
blend: None,
write_mask: wgpu::ColorWrites::ALL,
})],
}),
multiview: None,
cache: None,
});
let readback_buffer = image::ReadbackBuffers::new(&ctx.device, &texture);
{
let mut encoder = ctx
.device
.create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
{
let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
label: Some("Renderpass"),
color_attachments: &[Some(wgpu::RenderPassColorAttachment {
view: &texture_view,
resolve_target: None,
ops: wgpu::Operations {
// Important: this isn't the color expected below
load: wgpu::LoadOp::Clear(wgpu::Color {
r: 0.0,
g: 0.0,
b: 0.0,
a: 0.0,
}),
store: wgpu::StoreOp::Store,
},
})],
depth_stencil_attachment: None,
timestamp_writes: None,
occlusion_query_set: None,
});
render_pass.set_pipeline(&pipeline);
render_pass.draw(0..3, 0..1);
}
readback_buffer.copy_from(&ctx.device, &mut encoder, &texture);
ctx.queue.submit(Some(encoder.finish()));
}
let expected_data = [255; BUFFER_SIZE];
readback_buffer
.assert_buffer_contents(ctx, &expected_data)
.await;
}

108
tests/tests/regression/issue_4485.wgsl Normal file
View File

@ -0,0 +1,108 @@
// meant to be called with 3 vertex indices: 0, 1, 2
// draws one large triangle over the clip space like this:
// (the asterisks represent the clip space bounds)
//-1,1 1,1
// ---------------------------------
// | * .
// | * .
// | * .
// | * .
// | * .
// | * .
// |***************
// | . 1,-1
// | .
// | .
// | .
// | .
// |.
@vertex
fn vs_main(@builtin(vertex_index) vertex_index: u32) -> @builtin(position) vec4<f32> {
let x = i32(vertex_index) / 2;
let y = i32(vertex_index) & 1;
return vec4<f32>(
f32(x) * 4.0 - 1.0,
1.0 - f32(y) * 4.0,
0.0, 1.0
);
}
@fragment
fn fs_main() -> @location(0) vec4<f32> {
var x = 0.0;
loop {
if x != 0.0 { break; }
x = 0.5;
// Compiled to a do-while in hlsl and glsl,
// we want to confirm that continue applies to outer loop.
switch 0 {
default {
x = 1.0;
continue;
}
}
x = 0.0;
}
// expect X == 1.0
var y = 0.0;
loop {
if y != 0.0 { break; }
y = 0.5;
switch 1 {
case 0 {
continue;
}
case 1 {}
}
// test that loop doesn't continue after the switch when the continue case wasn't executed
y = 1.0;
break;
}
// expect y == 1.0
var z = 0.0;
loop {
if z != 0.0 { break; }
switch 0 {
case 0 {
z = 0.5;
}
case 1 {
z = 0.5;
}
}
// test that loop doesn't continue after the switch that contains no continue statements
z = 1.0
}
// expect z == 1.0
var w = 0.0;
loop {
if w != 0.0 { break; }
switch 0 {
case 0 {
loop {
// continue in loop->switch->loop->switch->switch should affect inner loop
switch 1 {
case 0 {}
case 1 {
switch 0 {
default { continue; }
}
}
}
w = 0.5
}
}
case 1 {
w = 0.5;
}
}
if w == 0.0 { w = 1.0; }
}
// expect w == 1.0
return vec4<f32>(x, y, z, w);
}

106
tests/tests/regression/issue_4514.rs Normal file
View File

@ -0,0 +1,106 @@
use wgpu_test::{gpu_test, image, GpuTestConfiguration, TestParameters, TestingContext};
/// FXC and potentially some glsl consumers have a bug when handling switch statements on a constant
/// with just a default case. (not sure if the constant part is relevant)
/// See <https://github.com/gfx-rs/wgpu/issues/4514>.
///
/// This test will fail on Dx12 with FXC if this issue is not worked around.
///
/// So far no specific buggy glsl consumers have been identified and it isn't known whether the
/// bug is avoided there.
#[gpu_test]
static DEGENERATE_SWITCH: GpuTestConfiguration = GpuTestConfiguration::new()
.parameters(TestParameters::default().force_fxc(true))
.run_async(|ctx| async move { test_impl(&ctx).await });
async fn test_impl(ctx: &TestingContext) {
const TEXTURE_HEIGHT: u32 = 2;
const TEXTURE_WIDTH: u32 = 2;
const BUFFER_SIZE: usize = (TEXTURE_WIDTH * TEXTURE_HEIGHT * 4) as usize;
let texture = ctx.device.create_texture(&wgpu::TextureDescriptor {
label: Some("Offscreen texture"),
size: wgpu::Extent3d {
width: TEXTURE_WIDTH,
height: TEXTURE_HEIGHT,
depth_or_array_layers: 1,
},
mip_level_count: 1,
sample_count: 1,
dimension: wgpu::TextureDimension::D2,
format: wgpu::TextureFormat::Rgba8Unorm,
usage: wgpu::TextureUsages::COPY_SRC | wgpu::TextureUsages::RENDER_ATTACHMENT,
view_formats: &[],
});
let texture_view = texture.create_view(&wgpu::TextureViewDescriptor::default());
let shader = ctx
.device
.create_shader_module(wgpu::include_wgsl!("issue_4514.wgsl"));
let pipeline = ctx
.device
.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
label: Some("Pipeline"),
layout: None,
vertex: wgpu::VertexState {
module: &shader,
entry_point: "vs_main",
compilation_options: Default::default(),
buffers: &[],
},
primitive: wgpu::PrimitiveState::default(),
depth_stencil: None,
multisample: wgpu::MultisampleState::default(),
fragment: Some(wgpu::FragmentState {
module: &shader,
entry_point: "fs_main",
compilation_options: Default::default(),
targets: &[Some(wgpu::ColorTargetState {
format: wgpu::TextureFormat::Rgba8Unorm,
blend: None,
write_mask: wgpu::ColorWrites::ALL,
})],
}),
multiview: None,
cache: None,
});
let readback_buffer = image::ReadbackBuffers::new(&ctx.device, &texture);
{
let mut encoder = ctx
.device
.create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
{
let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
label: Some("Renderpass"),
color_attachments: &[Some(wgpu::RenderPassColorAttachment {
view: &texture_view,
resolve_target: None,
ops: wgpu::Operations {
// Important: this isn't the color expected below
load: wgpu::LoadOp::Clear(wgpu::Color {
r: 0.0,
g: 0.0,
b: 0.0,
a: 0.0,
}),
store: wgpu::StoreOp::Store,
},
})],
depth_stencil_attachment: None,
timestamp_writes: None,
occlusion_query_set: None,
});
render_pass.set_pipeline(&pipeline);
render_pass.draw(0..3, 0..1);
}
readback_buffer.copy_from(&ctx.device, &mut encoder, &texture);
ctx.queue.submit(Some(encoder.finish()));
}
let expected_data = [255; BUFFER_SIZE];
readback_buffer
.assert_buffer_contents(ctx, &expected_data)
.await;
}

68
tests/tests/regression/issue_4514.wgsl Normal file
View File

@ -0,0 +1,68 @@
// meant to be called with 3 vertex indices: 0, 1, 2
// draws one large triangle over the clip space like this:
// (the asterisks represent the clip space bounds)
//-1,1 1,1
// ---------------------------------
// | * .
// | * .
// | * .
// | * .
// | * .
// | * .
// |***************
// | . 1,-1
// | .
// | .
// | .
// | .
// |.
@vertex
fn vs_main(@builtin(vertex_index) vertex_index: u32) -> @builtin(position) vec4<f32> {
let x = i32(vertex_index) / 2;
let y = i32(vertex_index) & 1;
return vec4<f32>(
f32(x) * 4.0 - 1.0,
1.0 - f32(y) * 4.0,
0.0, 1.0
);
}
@fragment
fn fs_main(@builtin(position) coord_in: vec4<f32>) -> @location(0) vec4<f32> {
var x = 0.0;
// Succeeds on FXC without workaround.
switch i32(coord_in.x) {
default {
x = 1.0;
}
}
var y = 0.0;
// Fails on FXC without workaround.
// (even if we adjust switch above to give different x values based on the input coord)
switch i32(x * 30.0) {
default {
y = 1.0;
}
}
var z = 0.0;
// Multiple cases with a single body also fails on FXC without a workaround.
switch 0 {
case 0, 2, default {
z = 1.0;
}
}
var w = 0.0;
// Succeeds on FXC without workaround.
switch 0 {
case 0 {
w = 1.0;
}
default {
w = 1.0;
}
}
return vec4<f32>(x, y, z, w);
}

2
tests/tests/root.rs
View File

@ -3,6 +3,8 @@ mod regression {
mod issue_3457;
mod issue_4024;
mod issue_4122;
mod issue_4485;
mod issue_4514;
mod issue_5553;
}