[TypePromotion] Only search for PHI + ZExt promotion of Integers

[avieira]

Summary

This fixes the breakage mentioned by @paulwalker-arm in D111237. We should only be searching for Type Promotions of Integers for PHI + ZExt.

[samparker]

LGTM. But, now I'm wondering whether we could handle vectors... ;p

[avieira]

Hehe, I don't see why not but that feels like another potential improvement rather than a fix ;) I'll go ahead and commit this to unblock @paulwalker-arm if that's OK?

llvm/lib/CodeGen/TypePromotion.cpp

bool TypePromotion::runOnFunction(Function &F) {
   };
 
   for (BasicBlock &BB : F) {
     for (Instruction &I : BB) {
       if (AllVisited.count(&I))
         continue;
 
       if (isa<ZExtInst>(&I) && isa<PHINode>(I.getOperand(0)) &&
-          BBIsInLoop(&BB)) {
+          isa<IntegerType>(I.getType()) && BBIsInLoop(&BB)) {
         LLVM_DEBUG(dbgs() << "IR Promotion: Searching from: " << I.getOperand(0)
                           << "\n");
         EVT ZExtVT = TLI->getValueType(DL, I.getType());
         Instruction *Phi = static_cast<Instruction *>(I.getOperand(0));
         MadeChange |= TryToPromote(Phi, ZExtVT.getFixedSizeInBits());
       } else if (auto *ICmp = dyn_cast<ICmpInst>(&I)) {
         // Search up from icmps to try to promote their operands.
         // Skip signed or pointer compares

llvm/test/Transforms/TypePromotion/AArch64/vla-zext.ll

+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -mtriple=aarch64 -type-promotion -verify -S %s -o - | FileCheck %s
+
+define dso_local void @foo(ptr nocapture noundef readonly %a, ptr nocapture noundef readonly %b, ptr nocapture noundef writeonly %c, i64 noundef %n) local_unnamed_addr {
+; CHECK-LABEL: @foo(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds i8, ptr [[B:%.*]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = load <vscale x 4 x i8>, ptr [[TMP0]], align 1
+; CHECK-NEXT:    [[TMP2:%.*]] = tail call i64 @llvm.vscale.i64()
+; CHECK-NEXT:    [[TMP3:%.*]] = shl nuw nsw i64 [[TMP2]], 3
+; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
+; CHECK:       vector.body:
+; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[B_VECTOR:%.*]] = phi <vscale x 4 x i8> [ [[TMP1]], [[ENTRY]] ], [ [[B_VECTOR_NEXT:%.*]], [[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[TMP4:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], i64 [[INDEX]]
+; CHECK-NEXT:    [[TMP5:%.*]] = load <vscale x 4 x i32>, ptr [[TMP4]], align 4
+; CHECK-NEXT:    [[TMP6:%.*]] = zext <vscale x 4 x i8> [[B_VECTOR]] to <vscale x 4 x i32>
+; CHECK-NEXT:    [[TMP7:%.*]] = add <vscale x 4 x i32> [[TMP5]], [[TMP6]]
+; CHECK-NEXT:    [[TMP8:%.*]] = getelementptr inbounds i32, ptr [[C:%.*]], i64 [[INDEX]]
+; CHECK-NEXT:    store <vscale x 4 x i32> [[TMP7]], ptr [[TMP8]], align 4
+; CHECK-NEXT:    [[TMP9:%.*]] = getelementptr inbounds i8, ptr [[B]], i64 [[INDEX]]
+; CHECK-NEXT:    [[B_VECTOR_NEXT]] = load <vscale x 4 x i8>, ptr [[TMP9]], align 1
+; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], [[TMP3]]
+; CHECK-NEXT:    [[TMP10:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[TMP10]], label [[END:%.*]], label [[VECTOR_BODY]]
+; CHECK:       end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = getelementptr inbounds i8, ptr %b, i64 0
+  %1 = load <vscale x 4 x i8>, ptr %0, align 1
+  %2 = tail call i64 @llvm.vscale.i64()
+  %3 = shl nuw nsw i64 %2, 3
+  br label %vector.body
+
+vector.body:                                              ; preds = %vector.body, %entry
+  %index = phi i64 [ 0, %entry ], [ %index.next, %vector.body ]
+  %b_vector = phi <vscale x 4 x i8> [ %1, %entry ], [ %b_vector.next, %vector.body ]
+  %4 = getelementptr inbounds i32, ptr %a, i64 %index
+  %5 = load <vscale x 4 x i32>, ptr %4, align 4
+  %6 = zext <vscale x 4 x i8> %b_vector to <vscale x 4 x i32>
+  %7 = add <vscale x 4 x i32> %5, %6
+  %8 = getelementptr inbounds i32, ptr %c, i64 %index
+  store <vscale x 4 x i32> %7, ptr %8, align 4
+  %9 = getelementptr inbounds i8, ptr %b, i64 %index
+  %b_vector.next = load <vscale x 4 x i8>, ptr %9, align 1
+  %index.next = add nuw i64 %index, %3
+  %10 = icmp eq i64 %index.next, %n
+  br i1 %10, label %end, label %vector.body
+
+end:                                                      ; preds = %vector.body
+  ret void
+}
+
+; Function Attrs: nocallback nofree nosync nounwind readnone willreturn
+declare i64 @llvm.vscale.i64()