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97717a5618
rust/src/test/codegen/stores.rs

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Rust
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Revamp codegen tests to check IR quality instead of quantity The current codegen tests only compare IR line counts between similar rust and C programs, the latter getting compiled with clang. That looked like a good idea back then, but actually things like lifetime intrinsics mean that less IR isn't always better, so the metric isn't really helpful. Instead, we can start doing tests that check specific aspects of the generated IR, like attributes or metadata. To do that, we can use LLVM's FileCheck tool which has a number of useful features for such tests. To start off, I created some tests for a few things that were recently added and/or broken.
2015-05-24 16:07:52 +00:00
// compile-flags: -C no-prepopulate-passes
Upgrade to LLVM's master branch (LLVM 7) This commit upgrades the main LLVM submodule to LLVM's current master branch. The LLD submodule is updated in tandem as well as compiler-builtins. Along the way support was also added for LLVM 7's new features. This primarily includes the support for custom section concatenation natively in LLD so we now add wasm custom sections in LLVM IR rather than having custom support in rustc itself for doing so. Some other miscellaneous changes are: * We now pass `--gc-sections` to `wasm-ld` * The optimization level is now passed to `wasm-ld` * A `--stack-first` option is passed to LLD to have stack overflow always cause a trap instead of corrupting static data * The wasm target for LLVM switched to `wasm32-unknown-unknown`. * The syntax for aligned pointers has changed in LLVM IR and tests are updated to reflect this. * The `thumbv6m-none-eabi` target is disabled due to an [LLVM bug][llbug] Nowadays we've been mostly only upgrading whenever there's a major release of LLVM but enough changes have been happening on the wasm target that there's been growing motivation for quite some time now to upgrade out version of LLD. To upgrade LLD, however, we need to upgrade LLVM to avoid needing to build yet another version of LLVM on the builders. The revision of LLVM in use here is arbitrarily chosen. We will likely need to continue to update it over time if and when we discover bugs. Once LLVM 7 is fully released we can switch to that channel as well. [llbug]: https://bugs.llvm.org/show_bug.cgi?id=37382
2018-06-01 17:20:00 +00:00
// ignore-tidy-linelength
Revamp codegen tests to check IR quality instead of quantity The current codegen tests only compare IR line counts between similar rust and C programs, the latter getting compiled with clang. That looked like a good idea back then, but actually things like lifetime intrinsics mean that less IR isn't always better, so the metric isn't really helpful. Instead, we can start doing tests that check specific aspects of the generated IR, like attributes or metadata. To do that, we can use LLVM's FileCheck tool which has a number of useful features for such tests. To start off, I created some tests for a few things that were recently added and/or broken.
2015-05-24 16:07:52 +00:00
Avoid loading the whole gdb debug scripts section. This is so LLVM isn't forced to load every byte of it. Also sets the alignment of the load. Adds a test for the debug script section.
2015-09-15 21:22:16 +00:00
#![crate_type = "lib"]
Revamp codegen tests to check IR quality instead of quantity The current codegen tests only compare IR line counts between similar rust and C programs, the latter getting compiled with clang. That looked like a good idea back then, but actually things like lifetime intrinsics mean that less IR isn't always better, so the metric isn't really helpful. Instead, we can start doing tests that check specific aspects of the generated IR, like attributes or metadata. To do that, we can use LLVM's FileCheck tool which has a number of useful features for such tests. To start off, I created some tests for a few things that were recently added and/or broken.
2015-05-24 16:07:52 +00:00
pub struct Bytes {
a: u8,
b: u8,
c: u8,
d: u8,
}
// CHECK-LABEL: small_array_alignment
// The array is stored as i32, but its alignment is lower, go with 1 byte to avoid target
// dependent alignment
#[no_mangle]
tests: Use arguments in codegen/stores.rs to turn aggregates into immediates.
2016-03-06 12:28:11 +00:00
pub fn small_array_alignment(x: &mut [i8; 4], y: [i8; 4]) {
trans: always use a memcpy for ABI argument/return casts.
2016-06-07 21:35:01 +00:00
// CHECK: [[TMP:%.+]] = alloca i32
Avoid unnecessary copies of arguments that are simple bindings Initially MIR differentiated between arguments and locals, which introduced a need to add extra copies assigning the argument to a local, even for simple bindings. This differentiation no longer exists, but we're still creating those copies, bloating the MIR and LLVM IR we emit. Additionally, the current approach means that we create debug info for both the incoming argument (marking it as an argument), and then immediately shadow it a local that goes by the same name. This can be confusing when using e.g. "info args" in gdb, or when e.g. a debugger with a GUI displays the function arguments separately from the local variables, especially when the binding is mutable, because the argument doesn't change, while the local variable does.
2017-10-11 18:49:36 +00:00
// CHECK: %y = alloca [4 x i8]
// CHECK: store i32 %0, i32* [[TMP]]
// CHECK: [[Y8:%[0-9]+]] = bitcast [4 x i8]* %y to i8*
trans: always use a memcpy for ABI argument/return casts.
2016-06-07 21:35:01 +00:00
// CHECK: [[TMP8:%[0-9]+]] = bitcast i32* [[TMP]] to i8*
Support memcpy/memmove with differing src/dst alignment If LLVM 7 is used, generate memcpy/memmove with differing src/dst alignment. I've added new FFI functions to construct these through the builder API, which is more convenient than dealing with differing intrinsic signatures depending on the LLVM version.
2018-11-02 22:38:16 +00:00
// CHECK: call void @llvm.memcpy.{{.*}}(i8* align 1 [[Y8]], i8* align 4 [[TMP8]], i{{[0-9]+}} 4, i1 false)
tests: Use arguments in codegen/stores.rs to turn aggregates into immediates.
2016-03-06 12:28:11 +00:00
*x = y;
Revamp codegen tests to check IR quality instead of quantity The current codegen tests only compare IR line counts between similar rust and C programs, the latter getting compiled with clang. That looked like a good idea back then, but actually things like lifetime intrinsics mean that less IR isn't always better, so the metric isn't really helpful. Instead, we can start doing tests that check specific aspects of the generated IR, like attributes or metadata. To do that, we can use LLVM's FileCheck tool which has a number of useful features for such tests. To start off, I created some tests for a few things that were recently added and/or broken.
2015-05-24 16:07:52 +00:00
}
// CHECK-LABEL: small_struct_alignment
// The struct is stored as i32, but its alignment is lower, go with 1 byte to avoid target
// dependent alignment
#[no_mangle]
tests: Use arguments in codegen/stores.rs to turn aggregates into immediates.
2016-03-06 12:28:11 +00:00
pub fn small_struct_alignment(x: &mut Bytes, y: Bytes) {
trans: always use a memcpy for ABI argument/return casts.
2016-06-07 21:35:01 +00:00
// CHECK: [[TMP:%.+]] = alloca i32
Avoid unnecessary copies of arguments that are simple bindings Initially MIR differentiated between arguments and locals, which introduced a need to add extra copies assigning the argument to a local, even for simple bindings. This differentiation no longer exists, but we're still creating those copies, bloating the MIR and LLVM IR we emit. Additionally, the current approach means that we create debug info for both the incoming argument (marking it as an argument), and then immediately shadow it a local that goes by the same name. This can be confusing when using e.g. "info args" in gdb, or when e.g. a debugger with a GUI displays the function arguments separately from the local variables, especially when the binding is mutable, because the argument doesn't change, while the local variable does.
2017-10-11 18:49:36 +00:00
// CHECK: %y = alloca %Bytes
// CHECK: store i32 %0, i32* [[TMP]]
// CHECK: [[Y8:%[0-9]+]] = bitcast %Bytes* %y to i8*
trans: always use a memcpy for ABI argument/return casts.
2016-06-07 21:35:01 +00:00
// CHECK: [[TMP8:%[0-9]+]] = bitcast i32* [[TMP]] to i8*
Support memcpy/memmove with differing src/dst alignment If LLVM 7 is used, generate memcpy/memmove with differing src/dst alignment. I've added new FFI functions to construct these through the builder API, which is more convenient than dealing with differing intrinsic signatures depending on the LLVM version.
2018-11-02 22:38:16 +00:00
// CHECK: call void @llvm.memcpy.{{.*}}(i8* align 1 [[Y8]], i8* align 4 [[TMP8]], i{{[0-9]+}} 4, i1 false)
tests: Use arguments in codegen/stores.rs to turn aggregates into immediates.
2016-03-06 12:28:11 +00:00
*x = y;
Revamp codegen tests to check IR quality instead of quantity The current codegen tests only compare IR line counts between similar rust and C programs, the latter getting compiled with clang. That looked like a good idea back then, but actually things like lifetime intrinsics mean that less IR isn't always better, so the metric isn't really helpful. Instead, we can start doing tests that check specific aspects of the generated IR, like attributes or metadata. To do that, we can use LLVM's FileCheck tool which has a number of useful features for such tests. To start off, I created some tests for a few things that were recently added and/or broken.
2015-05-24 16:07:52 +00:00
}
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