[llvm] 75c7019 - [amdgpu] Fix broken error detection in LDS lowering

[Jon Chesterfield via llvm-commits]

Author: Jon Chesterfield
Date: 2023-03-30T13:42:38+01:00
New Revision: 75c7019b7ea4a846575337fa5cf4f1780a2d5b74

URL: https://github.com/llvm/llvm-project/commit/75c7019b7ea4a846575337fa5cf4f1780a2d5b74
DIFF: https://github.com/llvm/llvm-project/commit/75c7019b7ea4a846575337fa5cf4f1780a2d5b74.diff

LOG: [amdgpu] Fix broken error detection in LDS lowering

std::optional<uint32_t> can be compared to uint32_t without warning, but does
not compare to the value within the optional. It needs to be prefixed *.
Wconversion does not warn about this.
```
bool bug(uint32_t Offset, std::optional<uint32_t> Expect)
{
  return (Offset != Expect);
}
bool deref(uint32_t Offset, std::optional<uint32_t> Expect)
{
  return (Offset != *Expect);
}
```
Both compile without warnings. Wrote the former, intended the latter.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D146775

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.cpp b/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.cpp
index e70afd72462e..6c6cc0127a2b 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.cpp
@@ -135,7 +135,7 @@ void AMDGPUMachineFunction::allocateKnownAddressLDSGlobal(const Function &F) {
     if (GV && !canElideModuleLDS(F)) {
       unsigned Offset = allocateLDSGlobal(M->getDataLayout(), *GV, Align());
       std::optional<uint32_t> Expect = getLDSAbsoluteAddress(*GV);
-      if (!Expect || (Offset != Expect)) {
+      if (!Expect || (Offset != *Expect)) {
         report_fatal_error("Inconsistent metadata on module LDS variable");
       }
     }
@@ -145,7 +145,7 @@ void AMDGPUMachineFunction::allocateKnownAddressLDSGlobal(const Function &F) {
       // before any other non-module LDS variables.
       unsigned Offset = allocateLDSGlobal(M->getDataLayout(), *KV, Align());
       std::optional<uint32_t> Expect = getLDSAbsoluteAddress(*KV);
-      if (!Expect || (Offset != Expect)) {
+      if (!Expect || (Offset != *Expect)) {
         report_fatal_error("Inconsistent metadata on kernel LDS variable");
       }
     }