Remove workaround for the forward progress handling in LLVM

This commit is contained in:
Andreas Jonson 2021-11-14 14:01:30 +01:00
parent f820d9d4e5
commit 50ec47aa06
5 changed files with 1 additions and 30 deletions

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@ -316,7 +316,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
extended_asm.add_input_operand(None, "r", result.llval);
extended_asm.add_clobber("memory");
extended_asm.set_volatile_flag(true);
// We have copied the value to `result` already.
return;
}
@ -363,10 +363,6 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
cond
}
fn sideeffect(&mut self) {
// TODO(antoyo)
}
fn type_test(&mut self, _pointer: Self::Value, _typeid: Self::Value) -> Self::Value {
// Unsupported.
self.context.new_rvalue_from_int(self.int_type, 0)

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@ -597,7 +597,6 @@ impl CodegenCx<'b, 'tcx> {
ifn!("llvm.trap", fn() -> void);
ifn!("llvm.debugtrap", fn() -> void);
ifn!("llvm.frameaddress", fn(t_i32) -> i8p);
ifn!("llvm.sideeffect", fn() -> void);
ifn!("llvm.powi.f32", fn(t_f32, t_i32) -> t_f32);
ifn!("llvm.powi.f64", fn(t_f64, t_i32) -> t_f64);

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@ -392,15 +392,6 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
self.call_intrinsic("llvm.expect.i1", &[cond, self.const_bool(expected)])
}
fn sideeffect(&mut self) {
// This kind of check would make a ton of sense in the caller, but currently the only
// caller of this function is in `rustc_codegen_ssa`, which is agnostic to whether LLVM
// codegen backend being used, and so is unable to check the LLVM version.
if unsafe { llvm::LLVMRustVersionMajor() } < 12 {
self.call_intrinsic("llvm.sideeffect", &[]);
}
}
fn type_test(&mut self, pointer: Self::Value, typeid: Self::Value) -> Self::Value {
// Test the called operand using llvm.type.test intrinsic. The LowerTypeTests link-time
// optimization pass replaces calls to this intrinsic with code to test type membership.

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@ -980,17 +980,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
}
mir::TerminatorKind::Goto { target } => {
if bb == target {
// This is an unconditional branch back to this same basic block. That means we
// have something like a `loop {}` statement. LLVM versions before 12.0
// miscompile this because they assume forward progress. For older versions
// try to handle just this specific case which comes up commonly in practice
// (e.g., in embedded code).
//
// NB: the `sideeffect` currently checks for the LLVM version used internally.
bx.sideeffect();
}
helper.funclet_br(self, &mut bx, target);
}

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@ -20,10 +20,6 @@ pub trait IntrinsicCallMethods<'tcx>: BackendTypes {
fn abort(&mut self);
fn assume(&mut self, val: Self::Value);
fn expect(&mut self, cond: Self::Value, expected: bool) -> Self::Value;
/// Emits a forced side effect.
///
/// Currently has any effect only when LLVM versions prior to 12.0 are used as the backend.
fn sideeffect(&mut self);
/// Trait method used to test whether a given pointer is associated with a type identifier.
fn type_test(&mut self, pointer: Self::Value, typeid: Self::Value) -> Self::Value;
/// Trait method used to inject `va_start` on the "spoofed" `VaListImpl` in