[llvm] [LLVM][ConstantFold] Ensure scalar type is queried when determining denormal mode. (PR #189600)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-analysis

Author: Paul Walker (paulwalker-arm)

<details>
<summary>Changes</summary>

Fixes https://github.com/llvm/llvm-project/issues/187928

---
Full diff: https://github.com/llvm/llvm-project/pull/189600.diff


2 Files Affected:

- (modified) llvm/lib/Analysis/ConstantFolding.cpp (+2-1) 
- (modified) llvm/test/Transforms/InstSimplify/constant-fold-fp-denormal.ll (+18) 


``````````diff
diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index e9eea82d60116..3c64ad6f6b369 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -1357,7 +1357,8 @@ static ConstantFP *flushDenormalConstant(Type *Ty, const APFloat &APF,
 static DenormalMode getInstrDenormalMode(const Instruction *CtxI, Type *Ty) {
   if (!CtxI || !CtxI->getParent() || !CtxI->getFunction())
     return DenormalMode::getDynamic();
-  return CtxI->getFunction()->getDenormalMode(Ty->getFltSemantics());
+  return CtxI->getFunction()->getDenormalMode(
+      Ty->getScalarType()->getFltSemantics());
 }
 
 static ConstantFP *flushDenormalConstantFP(ConstantFP *CFP,
diff --git a/llvm/test/Transforms/InstSimplify/constant-fold-fp-denormal.ll b/llvm/test/Transforms/InstSimplify/constant-fold-fp-denormal.ll
index 16d5f0d2871b1..39465bc1e5fe5 100644
--- a/llvm/test/Transforms/InstSimplify/constant-fold-fp-denormal.ll
+++ b/llvm/test/Transforms/InstSimplify/constant-fold-fp-denormal.ll
@@ -1,5 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -S -passes=instsimplify < %s | FileCheck %s
+; RUN: opt -S -passes=instsimplify -use-constant-fp-for-fixed-length-splat < %s | FileCheck %s
 
 ; Test cases for denormal handling mode when constant folding floating point
 ; operations. Input and output modes are checked separately.
@@ -1149,6 +1150,14 @@ define i1 @fcmp_double_dynamic_ieee() #9 {
   ret i1 %cmp
 }
 
+define <2 x i1> @fcmp_double_dynamic_ieee_vector() #9 {
+; CHECK-LABEL: @fcmp_double_dynamic_ieee_vector(
+; CHECK-NEXT:    ret <2 x i1> splat (i1 true)
+;
+  %cmp = fcmp une <2 x double> splat(double 0x0008000000000000), zeroinitializer
+  ret <2 x i1> %cmp
+}
+
 define i1 @fcmp_double_ieee_dynamic() #10 {
 ; CHECK-LABEL: @fcmp_double_ieee_dynamic(
 ; CHECK-NEXT:    [[CMP:%.*]] = fcmp une double 0x8000000000000, 0.000000e+00
@@ -1158,6 +1167,15 @@ define i1 @fcmp_double_ieee_dynamic() #10 {
   ret i1 %cmp
 }
 
+define <2 x i1> @fcmp_double_ieee_dynamic_vector() #10 {
+; CHECK-LABEL: @fcmp_double_ieee_dynamic_vector(
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp une <2 x double> splat (double 0x8000000000000), zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %cmp = fcmp une <2 x double> splat(double 0x0008000000000000), zeroinitializer
+  ret <2 x i1> %cmp
+}
+
 define i1 @fcmp_double_dynamic_dynamic() #11 {
 ; CHECK-LABEL: @fcmp_double_dynamic_dynamic(
 ; CHECK-NEXT:    [[CMP:%.*]] = fcmp une double 0x8000000000000, 0.000000e+00

``````````

</details>


https://github.com/llvm/llvm-project/pull/189600