[llvm] [LLVM][NumericalStabilitySanitizer] Add support for vector ConstantFPs. (PR #151739)

[Paul Walker via llvm-commits]

https://github.com/paulwalker-arm created https://github.com/llvm/llvm-project/pull/151739

None

>From 9d5c3f1fd21097ca5d3057040ac7ab2d3f265b4c Mon Sep 17 00:00:00 2001
From: Paul Walker <paul.walker at arm.com>
Date: Fri, 1 Aug 2025 17:27:57 +0000
Subject: [PATCH] [LLVM][NumericalStabilitySanitizer] Add support for vector
 ConstantFPs.

---
 .../Transforms/Instrumentation/NumericalStabilitySanitizer.cpp | 3 ++-
 llvm/test/Instrumentation/NumericalStabilitySanitizer/basic.ll | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp
index fa1db288fbb2e..d18c0d0d2d90d 100644
--- a/llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp
@@ -468,7 +468,8 @@ class ValueToShadowMap {
       // Floating-point constants.
       Type *Ty = Config.getExtendedFPType(CFP->getType());
       return ConstantFP::get(
-          Ty, extendConstantFP(CFP->getValueAPF(), Ty->getFltSemantics()));
+          Ty, extendConstantFP(CFP->getValueAPF(),
+                               Ty->getScalarType()->getFltSemantics()));
     }
     // Vector, array, or aggregate constants.
     if (C->getType()->isVectorTy()) {
diff --git a/llvm/test/Instrumentation/NumericalStabilitySanitizer/basic.ll b/llvm/test/Instrumentation/NumericalStabilitySanitizer/basic.ll
index 03c5e917f0765..434ac8462b624 100644
--- a/llvm/test/Instrumentation/NumericalStabilitySanitizer/basic.ll
+++ b/llvm/test/Instrumentation/NumericalStabilitySanitizer/basic.ll
@@ -2,6 +2,9 @@
 ; RUN: opt -passes=nsan -nsan-shadow-type-mapping=dqq -nsan-truncate-fcmp-eq=false -S %s | FileCheck %s --check-prefixes=CHECK,DQQ
 ; RUN: opt -passes=nsan -nsan-shadow-type-mapping=dlq -nsan-truncate-fcmp-eq=false -S %s | FileCheck %s --check-prefixes=CHECK,DLQ
 
+; RUN: opt -passes=nsan -nsan-shadow-type-mapping=dqq -nsan-truncate-fcmp-eq=false -use-constant-fp-for-fixed-length-splat -S %s | FileCheck %s --check-prefixes=CHECK,DQQ
+; RUN: opt -passes=nsan -nsan-shadow-type-mapping=dlq -nsan-truncate-fcmp-eq=false -use-constant-fp-for-fixed-length-splat -S %s | FileCheck %s --check-prefixes=CHECK,DLQ
+
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 
 declare float @declaration_only(float %a) sanitize_numerical_stability