[PATCH] D106288: [AMDGPU] Disable LDS lowering for GFX shaders

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec created this revision.
rampitec added reviewers: arsenm, dstuttard, mareko.
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Apparently these need external LDS symbols to remain.

Fixes: SC1-3279


https://reviews.llvm.org/D106288

Files:
  llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
  llvm/test/CodeGen/AMDGPU/lower-kernel-lds.ll


Index: llvm/test/CodeGen/AMDGPU/lower-kernel-lds.ll
===================================================================
--- llvm/test/CodeGen/AMDGPU/lower-kernel-lds.ll
+++ llvm/test/CodeGen/AMDGPU/lower-kernel-lds.ll
@@ -12,6 +12,7 @@
 
 ;.
 ; CHECK: @lds.size.8.align.8 = internal unnamed_addr addrspace(3) global [8 x i8] undef, align 8
+; CHECK: @lds.k2 = internal unnamed_addr addrspace(3) global [1 x i8] undef, align 1
 ; CHECK: @llvm.amdgcn.kernel.k0.lds = internal addrspace(3) global %llvm.amdgcn.kernel.k0.lds.t undef, align 16
 ; CHECK: @llvm.amdgcn.kernel.k1.lds = internal addrspace(3) global %llvm.amdgcn.kernel.k1.lds.t undef, align 16
 ;.
@@ -63,3 +64,19 @@
 
   ret void
 }
+
+; Do not lower LDS for graphics shaders.
+
+ at lds.k2 = internal unnamed_addr addrspace(3) global [1 x i8] undef, align 1
+
+define amdgpu_ps void @k2() {
+; CHECK-LABEL: @k2(
+; CHECK-NEXT:    %lds.k2.bc = bitcast [1 x i8] addrspace(3)* @lds.k2 to i8 addrspace(3)*
+; CHECK-NEXT:    store i8 1, i8 addrspace(3)* %lds.k2.bc, align 1
+; CHECK-NEXT:    ret void
+;
+  %lds.k2.bc = bitcast [1 x i8] addrspace(3)* @lds.k2 to i8 addrspace(3)*
+  store i8 1, i8 addrspace(3)* %lds.k2.bc, align 1
+
+  ret void
+}
Index: llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
+++ llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
@@ -162,7 +162,8 @@
     bool Changed = processUsedLDS(M);
 
     for (Function &F : M.functions()) {
-      if (!AMDGPU::isKernelCC(&F))
+      // Only lower compute kernels' LDS.
+      if (!AMDGPU::isKernel(F.getCallingConv()))
         continue;
       Changed |= processUsedLDS(M, &F);
     }


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