[PATCH] D83676: AMDGPUPerhHintAnalysis: don't treat constant loads as large stride

[Jay Foad via Phabricator via llvm-commits]

foad updated this revision to Diff 278156.
foad added a comment.

Add a test case.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83676/new/

https://reviews.llvm.org/D83676

Files:
  llvm/lib/Target/AMDGPU/AMDGPUPerfHintAnalysis.cpp
  llvm/test/CodeGen/AMDGPU/perfhint.ll


Index: llvm/test/CodeGen/AMDGPU/perfhint.ll
===================================================================
--- llvm/test/CodeGen/AMDGPU/perfhint.ll
+++ llvm/test/CodeGen/AMDGPU/perfhint.ll
@@ -49,6 +49,26 @@
   ret void
 }
 
+; GCN-LABEL: {{^}}test_constant_not_large_stride:
+; GCN: MemoryBound: 0
+; GCN: WaveLimiterHint : 0
+define amdgpu_kernel void @test_constant_not_large_stride(i32 addrspace(4)* nocapture %arg, i32 addrspace(1)* nocapture %arg1) {
+bb:
+  %tmp = getelementptr inbounds i32, i32 addrspace(4)* %arg, i64 4096
+  %tmp1 = load i32, i32 addrspace(4)* %tmp, align 4
+  %tmp3 = getelementptr inbounds i32, i32 addrspace(4)* %arg, i64 8192
+  %tmp4 = load i32, i32 addrspace(4)* %tmp3, align 4
+  %tmp6 = getelementptr inbounds i32, i32 addrspace(4)* %arg, i64 12288
+  %tmp7 = load i32, i32 addrspace(4)* %tmp6, align 4
+  %tmp2 = getelementptr inbounds i32, i32 addrspace(1)* %arg1, i64 1
+  store i32 %tmp1, i32 addrspace(1)* %tmp2, align 4
+  %tmp5 = getelementptr inbounds i32, i32 addrspace(1)* %arg1, i64 2
+  store i32 %tmp4, i32 addrspace(1)* %tmp5, align 4
+  %tmp8 = getelementptr inbounds i32, i32 addrspace(1)* %arg1, i64 3
+  store i32 %tmp7, i32 addrspace(1)* %tmp8, align 4
+  ret void
+}
+
 ; GCN-LABEL: {{^}}test_indirect:
 ; GCN: MemoryBound: 0
 ; GCN: WaveLimiterHint : 1
Index: llvm/lib/Target/AMDGPU/AMDGPUPerfHintAnalysis.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/AMDGPUPerfHintAnalysis.cpp
+++ llvm/lib/Target/AMDGPU/AMDGPUPerfHintAnalysis.cpp
@@ -333,6 +333,10 @@
   // Do not treat local-addr memory access as large stride.
   if (isLocalAddr(MO))
     return MAI;
+  // Do not treat constant-addr memory access as large stride because K$
+  // behavior is very different from L0$.
+  if (isConstantAddr(MO))
+    return MAI;
 
   MAI.V = MO;
   MAI.Base = GetPointerBaseWithConstantOffset(MO, MAI.Offset, *DL);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D83676.278156.patch
Type: text/x-patch
Size: 1918 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200715/1a8c8f6b/attachment.bin>