[AMDGPU] Fix HasFP32Denormals check in FDIV32 lowering

[Pierre-vh]

Fixes SWDEV-403219

[arsenm]

Missing test changes.

This is also a stop gap, we really need to address the fixme later and restore the correct mode

[llvmbot]

@llvm/pr-subscribers-llvm-globalisel

@llvm/pr-subscribers-backend-amdgpu

Changes

Fixes SWDEV-403219 -- Full diff: https://github.com//pull/66212.diff

1 Files Affected:

• (modified) llvm/lib/Target/AMDGPU/SIISelLowering.cpp (+1-1)

diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index 777fe76df1151cd..998904bf08820c0 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -9589,7 +9589,7 @@ SDValue SITargetLowering::LowerFDIV32(SDValue Op, SelectionDAG &DAG) const {
   const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
   const DenormalMode DenormMode = Info->getMode().FP32Denormals;
 
-  const bool HasFP32Denormals = DenormMode == DenormalMode::getIEEE();
+  const bool HasFP32Denormals = DenormMode != DenormalMode::getPreserveSign();
 
   if (!HasFP32Denormals) {
     // Note we can't use the STRICT_FMA/STRICT_FMUL for the non-strict FDIV

[arsenm]

Also need the equivalent change for globalisel

[arsenm]

Please fix the dynamic mode restore in a follow up

[arsenm]

This is still broken, we're just changing the mode incorrectly in the other direction