[llvm-branch-commits] [llvm] AMDGPU: Move fpenvIEEEMode into TTI (PR #141945)

[Matt Arsenault via llvm-branch-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/141945

None

>From dc0d24948146621e6ba5e39c21ea7f4494a14ed1 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Thu, 29 May 2025 11:16:22 +0200
Subject: [PATCH] AMDGPU: Move fpenvIEEEMode into TTI

---
 .../AMDGPU/AMDGPUInstCombineIntrinsic.cpp     | 28 ++-----------------
 .../AMDGPU/AMDGPUTargetTransformInfo.cpp      | 17 +++++++++++
 .../Target/AMDGPU/AMDGPUTargetTransformInfo.h |  7 +++++
 3 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
index 5f6ab24182d5e..b0774385547c6 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
@@ -60,28 +60,6 @@ static APFloat fmed3AMDGCN(const APFloat &Src0, const APFloat &Src1,
   return maxnum(Src0, Src1);
 }
 
-enum class KnownIEEEMode { Unknown, On, Off };
-
-/// Return KnownIEEEMode::On if we know if the use context can assume
-/// "amdgpu-ieee"="true" and KnownIEEEMode::Off if we can assume
-/// "amdgpu-ieee"="false".
-static KnownIEEEMode fpenvIEEEMode(const Instruction &I,
-                                   const GCNSubtarget &ST) {
-  if (!ST.hasIEEEMode()) // Only mode on gfx12
-    return KnownIEEEMode::On;
-
-  const Function *F = I.getFunction();
-  if (!F)
-    return KnownIEEEMode::Unknown;
-
-  Attribute IEEEAttr = F->getFnAttribute("amdgpu-ieee");
-  if (IEEEAttr.isValid())
-    return IEEEAttr.getValueAsBool() ? KnownIEEEMode::On : KnownIEEEMode::Off;
-
-  return AMDGPU::isShader(F->getCallingConv()) ? KnownIEEEMode::Off
-                                               : KnownIEEEMode::On;
-}
-
 // Check if a value can be converted to a 16-bit value without losing
 // precision.
 // The value is expected to be either a float (IsFloat = true) or an unsigned
@@ -1003,7 +981,7 @@ GCNTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const {
     // TODO: Also can fold to 2 operands with infinities.
     if ((match(Src0, m_APFloat(ConstSrc0)) && ConstSrc0->isNaN()) ||
         isa<UndefValue>(Src0)) {
-      switch (fpenvIEEEMode(II, *ST)) {
+      switch (fpenvIEEEMode(II)) {
       case KnownIEEEMode::On:
         // TODO: If Src2 is snan, does it need quieting?
         if (ConstSrc0 && ConstSrc0->isSignaling())
@@ -1018,7 +996,7 @@ GCNTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const {
       }
     } else if ((match(Src1, m_APFloat(ConstSrc1)) && ConstSrc1->isNaN()) ||
                isa<UndefValue>(Src1)) {
-      switch (fpenvIEEEMode(II, *ST)) {
+      switch (fpenvIEEEMode(II)) {
       case KnownIEEEMode::On:
         // TODO: If Src2 is snan, does it need quieting?
         if (ConstSrc1 && ConstSrc1->isSignaling())
@@ -1034,7 +1012,7 @@ GCNTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const {
       }
     } else if ((match(Src2, m_APFloat(ConstSrc2)) && ConstSrc2->isNaN()) ||
                isa<UndefValue>(Src2)) {
-      switch (fpenvIEEEMode(II, *ST)) {
+      switch (fpenvIEEEMode(II)) {
       case KnownIEEEMode::On:
         if (ConstSrc2 && ConstSrc2->isSignaling()) {
           auto *Quieted = ConstantFP::get(II.getType(), ConstSrc2->makeQuiet());
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
index c1ccc8f6798a6..563c46f57dfa5 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
@@ -1445,3 +1445,20 @@ void GCNTTIImpl::collectKernelLaunchBounds(
   LB.push_back({"amdgpu-waves-per-eu[0]", WavesPerEU.first});
   LB.push_back({"amdgpu-waves-per-eu[1]", WavesPerEU.second});
 }
+
+GCNTTIImpl::KnownIEEEMode
+GCNTTIImpl::fpenvIEEEMode(const Instruction &I) const {
+  if (!ST->hasIEEEMode()) // Only mode on gfx12
+    return KnownIEEEMode::On;
+
+  const Function *F = I.getFunction();
+  if (!F)
+    return KnownIEEEMode::Unknown;
+
+  Attribute IEEEAttr = F->getFnAttribute("amdgpu-ieee");
+  if (IEEEAttr.isValid())
+    return IEEEAttr.getValueAsBool() ? KnownIEEEMode::On : KnownIEEEMode::Off;
+
+  return AMDGPU::isShader(F->getCallingConv()) ? KnownIEEEMode::Off
+                                               : KnownIEEEMode::On;
+}
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h
index ec298c7e9631a..0fae301abf532 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h
@@ -281,6 +281,13 @@ class GCNTTIImpl final : public BasicTTIImplBase<GCNTTIImpl> {
   void collectKernelLaunchBounds(
       const Function &F,
       SmallVectorImpl<std::pair<StringRef, int64_t>> &LB) const override;
+
+  enum class KnownIEEEMode { Unknown, On, Off };
+
+  /// Return KnownIEEEMode::On if we know if the use context can assume
+  /// "amdgpu-ieee"="true" and KnownIEEEMode::Off if we can assume
+  /// "amdgpu-ieee"="false".
+  KnownIEEEMode fpenvIEEEMode(const Instruction &I) const;
 };
 
 } // end namespace llvm