[llvm] [AMDGPU] Assert if stack grows downwards while lowering dynAlloca (PR #119888)

[Christudasan Devadasan via llvm-commits]

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@@ -1181,8 +1181,8 @@ bool AMDGPURegisterBankInfo::applyMappingDynStackAlloc(
 
   // Guard in case the stack growth direction ever changes with scratch
   // instructions.
-  if (TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown)
-    return false;
+  assert(TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsUp &&
+         "Stack grows upwards for AMDGPU\n");
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cdevadas wrote:

No need for \n at the end.

https://github.com/llvm/llvm-project/pull/119888