bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Don't set fast(-math) for certain simd ops

Browse source 
`fast-math` implies things like functions not being able to accept as an
argument or return as a result, say, `inf` which made these functions
confusingly named or behaving incorrectly, depending on how you
interpret it. Since the time when these intrinsics have been implemented
the intrinsics user's (stdsimd) approach has changed significantly and
so now it is required that these intrinsics operate normally rather than
in "whatever" way.

Fixes #84268
This commit is contained in:
Simonas Kazlauskas 2021-04-17 20:40:59 +03:00
parent cd9b30527e
commit 487e27350a
19 changed files with 154 additions and 131 deletions
Download patch file Download diff file Expand all files Collapse all files

18
compiler/rustc_codegen_llvm/src/builder.rs
View file

@ -261,7 +261,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
fn fadd_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
unsafe {
let instr = llvm::LLVMBuildFAdd(self.llbuilder, lhs, rhs, UNNAMED);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}
@ -269,7 +269,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
fn fsub_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
unsafe {
let instr = llvm::LLVMBuildFSub(self.llbuilder, lhs, rhs, UNNAMED);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}
@ -277,7 +277,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
fn fmul_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
unsafe {
let instr = llvm::LLVMBuildFMul(self.llbuilder, lhs, rhs, UNNAMED);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}
@ -285,7 +285,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
fn fdiv_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
unsafe {
let instr = llvm::LLVMBuildFDiv(self.llbuilder, lhs, rhs, UNNAMED);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}
@ -293,7 +293,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
fn frem_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
unsafe {
let instr = llvm::LLVMBuildFRem(self.llbuilder, lhs, rhs, UNNAMED);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}
@ -1242,14 +1242,14 @@ impl Builder<'a, 'll, 'tcx> {
pub fn vector_reduce_fadd_fast(&mut self, acc: &'ll Value, src: &'ll Value) -> &'ll Value {
unsafe {
let instr = llvm::LLVMRustBuildVectorReduceFAdd(self.llbuilder, acc, src);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}
pub fn vector_reduce_fmul_fast(&mut self, acc: &'ll Value, src: &'ll Value) -> &'ll Value {
unsafe {
let instr = llvm::LLVMRustBuildVectorReduceFMul(self.llbuilder, acc, src);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}
@ -1282,7 +1282,7 @@ impl Builder<'a, 'll, 'tcx> {
unsafe {
let instr =
llvm::LLVMRustBuildVectorReduceFMin(self.llbuilder, src, /*NoNaNs:*/ true);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}
@ -1290,7 +1290,7 @@ impl Builder<'a, 'll, 'tcx> {
unsafe {
let instr =
llvm::LLVMRustBuildVectorReduceFMax(self.llbuilder, src, /*NoNaNs:*/ true);
llvm::LLVMRustSetHasUnsafeAlgebra(instr);
llvm::LLVMRustSetFastMath(instr);
instr
}
}

40
compiler/rustc_codegen_llvm/src/intrinsic.rs
View file

@ -1053,50 +1053,48 @@ fn generic_simd_intrinsic(
let vec_ty = bx.type_vector(elem_ty, in_len);
let (intr_name, fn_ty) = match name {
sym::simd_fsqrt => ("sqrt", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fsin => ("sin", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fcos => ("cos", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fabs => ("fabs", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_ceil => ("ceil", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_floor => ("floor", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_round => ("round", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_trunc => ("trunc", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fexp => ("exp", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fabs => ("fabs", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fcos => ("cos", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fexp2 => ("exp2", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fexp => ("exp", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_flog10 => ("log10", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_flog2 => ("log2", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_flog => ("log", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_floor => ("floor", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fma => ("fma", bx.type_func(&[vec_ty, vec_ty, vec_ty], vec_ty)),
sym::simd_fpowi => ("powi", bx.type_func(&[vec_ty, bx.type_i32()], vec_ty)),
sym::simd_fpow => ("pow", bx.type_func(&[vec_ty, vec_ty], vec_ty)),
sym::simd_fma => ("fma", bx.type_func(&[vec_ty, vec_ty, vec_ty], vec_ty)),
sym::simd_fsin => ("sin", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_fsqrt => ("sqrt", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_round => ("round", bx.type_func(&[vec_ty], vec_ty)),
sym::simd_trunc => ("trunc", bx.type_func(&[vec_ty], vec_ty)),
_ => return_error!("unrecognized intrinsic `{}`", name),
};
let llvm_name = &format!("llvm.{0}.v{1}{2}", intr_name, in_len, elem_ty_str);
let f = bx.declare_cfn(&llvm_name, llvm::UnnamedAddr::No, fn_ty);
let c = bx.call(f, &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(), None);
unsafe { llvm::LLVMRustSetHasUnsafeAlgebra(c) };
Ok(c)
}
if std::matches!(
name,
sym::simd_fsqrt
| sym::simd_fsin
| sym::simd_fcos
sym::simd_ceil
| sym::simd_fabs
| sym::simd_ceil
| sym::simd_floor
| sym::simd_round
| sym::simd_trunc
| sym::simd_fexp
| sym::simd_fcos
| sym::simd_fexp2
| sym::simd_fexp
| sym::simd_flog10
| sym::simd_flog2
| sym::simd_flog
| sym::simd_fpowi
| sym::simd_fpow
| sym::simd_floor
| sym::simd_fma
| sym::simd_fpow
| sym::simd_fpowi
| sym::simd_fsin
| sym::simd_fsqrt
| sym::simd_round
| sym::simd_trunc
) {
return simd_simple_float_intrinsic(name, in_elem, in_ty, in_len, bx, span, args);
}

2
compiler/rustc_codegen_llvm/src/llvm/ffi.rs
View file

@ -1354,7 +1354,7 @@ extern "C" {
pub fn LLVMBuildNeg(B: &Builder<'a>, V: &'a Value, Name: *const c_char) -> &'a Value;
pub fn LLVMBuildFNeg(B: &Builder<'a>, V: &'a Value, Name: *const c_char) -> &'a Value;
pub fn LLVMBuildNot(B: &Builder<'a>, V: &'a Value, Name: *const c_char) -> &'a Value;
pub fn LLVMRustSetHasUnsafeAlgebra(Instr: &Value);
pub fn LLVMRustSetFastMath(Instr: &Value);
// Memory
pub fn LLVMBuildAlloca(B: &Builder<'a>, Ty: &'a Type, Name: *const c_char) -> &'a Value;