Skip to content

[SPIRV] Added support for the constrained arithmetic(Fmuladd) intrinsic #170270

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
SubashBoopathi wants to merge 4 commits into
base: main
Choose a base branch
from
+86 −0
Open

[SPIRV] Added support for the constrained arithmetic(Fmuladd) intrinsic #170270

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
589c1b9
[SPIRV] Added Support for constrained fmuladd intrinsic
SubashBoopathi Dec 2, 2025
38350b4
Merge branch 'main' into Constrained_fmad_intrinsic
SubashBoopathi Dec 2, 2025
a758883
Merge branch 'main' into Constrained_fmad_intrinsic
SubashBoopathi Dec 2, 2025
ae1dc38
Merge branch 'main' into Constrained_fmad_intrinsic
SubashBoopathi Dec 3, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 22 additions & 0 deletions llvm/lib/Target/SPIRV/SPIRVPrepareFunctions.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -393,6 +393,24 @@ static bool toSpvLifetimeIntrinsic(IntrinsicInst *II, Intrinsic::ID NewID) {
return true;
}

static void
lowerConstrainedFmuladd(IntrinsicInst *II,
SmallVector<Instruction *> &EraseFromParent) {
auto *FPI = cast<ConstrainedFPIntrinsic>(II);
Value *A = FPI->getArgOperand(0);
Value *Mul = FPI->getArgOperand(1);
Value *Add = FPI->getArgOperand(2);
IRBuilder<> Builder(II->getParent());
Builder.SetInsertPoint(II);
std::optional<RoundingMode> Rounding = FPI->getRoundingMode();
Value *Product = Builder.CreateFMul(A, Mul, II->getName() + ".mul");
Value *Result = Builder.CreateConstrainedFPBinOp(
Intrinsic::experimental_constrained_fadd, Product, Add, {},
II->getName() + ".add", nullptr, Rounding);
II->replaceAllUsesWith(Result);
EraseFromParent.push_back(II);
}

// Substitutes calls to LLVM intrinsics with either calls to SPIR-V intrinsics
// or calls to proper generated functions. Returns True if F was modified.
bool SPIRVPrepareFunctions::substituteIntrinsicCalls(Function *F) {
Expand Down Expand Up @@ -446,6 +464,10 @@ bool SPIRVPrepareFunctions::substituteIntrinsicCalls(Function *F) {
lowerPtrAnnotation(II);
Changed = true;
break;
case Intrinsic::experimental_constrained_fmuladd:
lowerConstrainedFmuladd(II, EraseFromParent);
Changed = true;
break;
case Intrinsic::experimental_constrained_fcmp:
case Intrinsic::experimental_constrained_fcmps:
lowerConstrainedFPCmpIntrinsic(dyn_cast<ConstrainedFPCmpIntrinsic>(II),
Expand Down
64 changes: 64 additions & 0 deletions llvm/test/CodeGen/SPIRV/llvm-intrinsics/constrained-fmuladd.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,64 @@
; RUN: llc -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
; RUN: %if spirv-tools %{ llc -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}

; CHECK-DAG: OpDecorate %[[#]] FPRoundingMode RTE
; CHECK-DAG: OpDecorate %[[#]] FPRoundingMode RTZ
; CHECK-DAG: OpDecorate %[[#]] FPRoundingMode RTP
; CHECK-DAG: OpDecorate %[[#]] FPRoundingMode RTN
; CHECK-DAG: OpDecorate %[[#]] FPRoundingMode RTE

; CHECK: OpFMul %[[#]] %[[#]] %[[#]]
; CHECK: OpFAdd %[[#]] %[[#]] %[[#]]
define spir_kernel void @test_f32(float %a) {
entry:
%r = tail call float @llvm.experimental.constrained.fmuladd.f32(
float %a, float %a, float %a,
metadata !"round.tonearest", metadata !"fpexcept.strict")
ret void
}

; CHECK: OpFMul %[[#]] %[[#]] %[[#]]
; CHECK: OpFAdd %[[#]] %[[#]] %[[#]]
define spir_kernel void @test_f64(double %a) {
entry:
%r = tail call double @llvm.experimental.constrained.fmuladd.f64(
double %a, double %a, double %a,
metadata !"round.towardzero", metadata !"fpexcept.strict")
ret void
}

; CHECK: OpFMul %[[#]] %[[#]] %[[#]]
; CHECK: OpFAdd %[[#]] %[[#]] %[[#]]
define spir_kernel void @test_v2f32(<2 x float> %a) {
entry:
%r = tail call <2 x float> @llvm.experimental.constrained.fmuladd.v2f32(
<2 x float> %a, <2 x float> %a, <2 x float> %a,
metadata !"round.upward", metadata !"fpexcept.strict")
ret void
}

; CHECK: OpFMul %[[#]] %[[#]] %[[#]]
; CHECK: OpFAdd %[[#]] %[[#]] %[[#]]
define spir_kernel void @test_v4f32(<4 x float> %a) {
entry:
%r = tail call <4 x float> @llvm.experimental.constrained.fmuladd.v4f32(
<4 x float> %a, <4 x float> %a, <4 x float> %a,
metadata !"round.downward", metadata !"fpexcept.strict")
ret void
}

; CHECK: OpFMul %[[#]] %[[#]] %[[#]]
; CHECK: OpFAdd %[[#]] %[[#]] %[[#]]
define spir_kernel void @test_v2f64(<2 x double> %a) {
entry:
%r = tail call <2 x double> @llvm.experimental.constrained.fmuladd.v2f64(
<2 x double> %a, <2 x double> %a, <2 x double> %a,
metadata !"round.tonearest", metadata !"fpexcept.strict")
ret void
}

declare float @llvm.experimental.constrained.fmuladd.f32(float, float, float, metadata, metadata)
declare double @llvm.experimental.constrained.fmuladd.f64(double, double, double, metadata, metadata)
declare <2 x float> @llvm.experimental.constrained.fmuladd.v2f32(<2 x float>, <2 x float>, <2 x float>, metadata, metadata)
declare <4 x float> @llvm.experimental.constrained.fmuladd.v4f32(<4 x float>, <4 x float>, <4 x float>, metadata, metadata)
declare <2 x double> @llvm.experimental.constrained.fmuladd.v2f64(<2 x double>, <2 x double>, <2 x double>, metadata, metadata)