[SROA] `isVectorPromotionViable()`: integer-ify non-pointer non-common types

This rectifies a FIXME that dates all the way back
to 2014 about not doing so due to the backend issues.

Presumably sufficient amount of time has passes
and all the known issues have been addressed,
or at least we will find out of there are some left...

diff --git a/llvm/lib/Transforms/Scalar/SROA.cpp b/llvm/lib/Transforms/Scalar/SROA.cpp
index 74bdfda..0d04565 100644 (file)
--- a/llvm/lib/Transforms/Scalar/SROA.cpp
+++ b/llvm/lib/Transforms/Scalar/SROA.cpp
@@ -1953,17 +1953,12 @@ static VectorType *isVectorPromotionViable(Partition &P, const DataLayout &DL) {
     CandidateTys.clear();
     CandidateTys.push_back(CommonVecPtrTy);
   } else if (!HaveCommonEltTy && !HaveVecPtrTy) {
-    // Remove non-integer vector types if we had multiple common element types.
-    // FIXME: It'd be nice to replace them with integer vector types, but we
-    // can't do that until all the backends are known to produce good code for
-    // all integer vector types.
-    llvm::erase_if(CandidateTys, [](VectorType *VTy) {
-      return !VTy->getElementType()->isIntegerTy();
-    });
-
-    // If there were no integer vector types, give up.
-    if (CandidateTys.empty())
-      return nullptr;
+    // Integer-ify vector types.
+    for (VectorType *&VTy : CandidateTys) {
+      if (!VTy->getElementType()->isIntegerTy())
+        VTy = cast<VectorType>(VTy->getWithNewType(IntegerType::getIntNTy(
+            VTy->getContext(), VTy->getScalarSizeInBits())));
+    }
 
     // Rank the remaining candidate vector types. This is easy because we know
     // they're all integer vectors. We sort by ascending number of elements.

diff --git a/llvm/test/Transforms/SROA/vector-promotion.ll b/llvm/test/Transforms/SROA/vector-promotion.ll
index aed0d50..1447bed 100644 (file)
--- a/llvm/test/Transforms/SROA/vector-promotion.ll
+++ b/llvm/test/Transforms/SROA/vector-promotion.ll
@@ -534,10 +534,9 @@ define <2 x float> @test11(<4 x i16> %x, i32 %y) {
 ; heuristic for making a deterministic decision.
 ; CHECK-LABEL: @test11(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TMP0:%.*]] = bitcast i32 [[Y:%.*]] to <2 x i16>
-; CHECK-NEXT:    [[A_SROA_0_4_VEC_EXPAND:%.*]] = shufflevector <2 x i16> [[TMP0]], <2 x i16> poison, <4 x i32> <i32 undef, i32 undef, i32 0, i32 1>
-; CHECK-NEXT:    [[A_SROA_0_4_VECBLEND:%.*]] = select <4 x i1> <i1 false, i1 false, i1 true, i1 true>, <4 x i16> [[A_SROA_0_4_VEC_EXPAND]], <4 x i16> [[X:%.*]]
-; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <4 x i16> [[A_SROA_0_4_VECBLEND]] to <2 x float>
+; CHECK-NEXT:    [[TMP0:%.*]] = bitcast <4 x i16> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[A_SROA_0_4_VEC_INSERT:%.*]] = insertelement <2 x i32> [[TMP0]], i32 [[Y:%.*]], i32 1
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <2 x i32> [[A_SROA_0_4_VEC_INSERT]] to <2 x float>
 ; CHECK-NEXT:    ret <2 x float> [[TMP1]]
 ;
 entry: