[LLVM][CostModel] Support struct types in select

[ivanradanov]

https://godbolt.org/z/b3TYcq7dv

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

@llvm/pr-subscribers-backend-x86

Author: Ivan R. Ivanov (ivanradanov)

Changes

https://godbolt.org/z/b3TYcq7dv

---

Full diff: https://github.com/llvm/llvm-project/pull/144016.diff

2 Files Affected:

• (modified) llvm/include/llvm/CodeGen/BasicTTIImpl.h (+5)
• (modified) llvm/test/Analysis/CostModel/X86/select.ll (+24)

diff --git a/llvm/include/llvm/CodeGen/BasicTTIImpl.h b/llvm/include/llvm/CodeGen/BasicTTIImpl.h
index 574152e254f15..9208f76f020f5 100644
--- a/llvm/include/llvm/CodeGen/BasicTTIImpl.h
+++ b/llvm/include/llvm/CodeGen/BasicTTIImpl.h
@@ -1370,6 +1370,11 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
       return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, CostKind,
                                        Op1Info, Op2Info, I);
 
+    // Structs etc
+    if (getTLI()->getValueType(DL, ValTy, true) == MVT::Other)
+      return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, CostKind,
+                                       Op1Info, Op2Info, I);
+
     // Selects on vectors are actually vector selects.
     if (ISD == ISD::SELECT) {
       assert(CondTy && "CondTy must exist");
diff --git a/llvm/test/Analysis/CostModel/X86/select.ll b/llvm/test/Analysis/CostModel/X86/select.ll
index f2c2890a182fc..e7e12178db3f3 100644
--- a/llvm/test/Analysis/CostModel/X86/select.ll
+++ b/llvm/test/Analysis/CostModel/X86/select.ll
@@ -554,3 +554,27 @@ define <32 x i8> @test_32i8(<32 x i8> %a, <32 x i8> %b) {
   ret <32 x i8> %sel
 }
 
+define { ptr, ptr } @test_struct( { ptr, ptr } %a, { ptr, ptr } %b, i1 %c) {
+; SSE-LABEL: 'test_struct'
+; SSE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction:   %sel = select i1 %c, { ptr, ptr } %a, { ptr, ptr } %b
+; SSE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction:   ret { ptr, ptr } %sel
+;
+; AVX1-LABEL: 'test_struct'
+; AVX1-NEXT:  Cost Model: Found an estimated cost of 1 for instruction:   %sel = select i1 %c, { ptr, ptr } %a, { ptr, ptr } %b
+; AVX1-NEXT:  Cost Model: Found an estimated cost of 0 for instruction:   ret { ptr, ptr } %sel
+;
+; AVX2-LABEL: 'test_struct'
+; AVX2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction:   %sel = select i1 %c, { ptr, ptr } %a, { ptr, ptr } %b
+; AVX2-NEXT:  Cost Model: Found an estimated cost of 0 for instruction:   ret { ptr, ptr } %sel
+;
+; AVX512-LABEL: 'test_struct'
+; AVX512-NEXT:  Cost Model: Found an estimated cost of 1 for instruction:   %sel = select i1 %c, { ptr, ptr } %a, { ptr, ptr } %b
+; AVX512-NEXT:  Cost Model: Found an estimated cost of 0 for instruction:   ret { ptr, ptr } %sel
+;
+; SLM-LABEL: 'test_struct'
+; SLM-NEXT:  Cost Model: Found an estimated cost of 1 for instruction:   %sel = select i1 %c, { ptr, ptr } %a, { ptr, ptr } %b
+; SLM-NEXT:  Cost Model: Found an estimated cost of 0 for instruction:   ret { ptr, ptr } %sel
+;
+  %sel = select i1 %c, { ptr, ptr } %a, { ptr, ptr } %b
+  ret { ptr, ptr } %sel
+}

[ivanradanov]

@s-barannikov Hello, sorry for the ping (I saw that you are involved in this part of the code) Would you know who can take a look at this?