diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/GVNHoist.cpp | 12 | ||||
| -rw-r--r-- | llvm/test/Transforms/GVN/pr28626.ll | 42 |
2 files changed, 50 insertions, 4 deletions
diff --git a/llvm/lib/Transforms/Scalar/GVNHoist.cpp b/llvm/lib/Transforms/Scalar/GVNHoist.cpp index c40068c5138..494f36bb3a7 100644 --- a/llvm/lib/Transforms/Scalar/GVNHoist.cpp +++ b/llvm/lib/Transforms/Scalar/GVNHoist.cpp @@ -576,16 +576,20 @@ public: bool makeOperandsAvailable(Instruction *Repl, BasicBlock *HoistPt) const { // Check whether the GEP of a ld/st can be synthesized at HoistPt. - Instruction *Gep = nullptr; + GetElementPtrInst *Gep = nullptr; Instruction *Val = nullptr; if (auto *Ld = dyn_cast<LoadInst>(Repl)) - Gep = dyn_cast<Instruction>(Ld->getPointerOperand()); + Gep = dyn_cast<GetElementPtrInst>(Ld->getPointerOperand()); if (auto *St = dyn_cast<StoreInst>(Repl)) { - Gep = dyn_cast<Instruction>(St->getPointerOperand()); + Gep = dyn_cast<GetElementPtrInst>(St->getPointerOperand()); Val = dyn_cast<Instruction>(St->getValueOperand()); } - if (!Gep || !isa<GetElementPtrInst>(Gep)) + if (!Gep) + return false; + + // PHIs may only be inserted at the start of a block. + if (Val && isa<PHINode>(Val)) return false; // Check whether we can compute the Gep at HoistPt. diff --git a/llvm/test/Transforms/GVN/pr28626.ll b/llvm/test/Transforms/GVN/pr28626.ll new file mode 100644 index 00000000000..742d968be36 --- /dev/null +++ b/llvm/test/Transforms/GVN/pr28626.ll @@ -0,0 +1,42 @@ +; RUN: opt -S -gvn-hoist < %s | FileCheck %s +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define void @test1(i1 %a, i1** %d) { +entry: + %0 = load i1*, i1** %d, align 8 + br i1 %a, label %if.then, label %if.else + +if.then: ; preds = %entry + br label %if.end + +if.else: ; preds = %entry + br label %if.end + +if.end: ; preds = %if.else, %if.then + %c.0 = phi i1 [ 1, %if.then ], [ 0, %if.else ] + br i1 %c.0, label %if.then2, label %if.else3 + +if.then2: ; preds = %if.end + %rc = getelementptr inbounds i1, i1* %0, i64 0 + store i1 %c.0, i1* %rc, align 4 + br label %if.end6 + +if.else3: ; preds = %if.end + %rc5 = getelementptr inbounds i1, i1* %0, i64 0 + store i1 %c.0, i1* %rc5, align 4 + br label %if.end6 + +if.end6: ; preds = %if.else3, %if.then2 + ret void +} + +; CHECK-LABEL: define void @test1( +; CHECK: %[[load:.*]] = load i1*, i1** %d, align 8 +; CHECK: %[[phi:.*]] = phi i1 [ true, {{.*}} ], [ false, {{.*}} ] + +; CHECK: %[[gep0:.*]] = getelementptr inbounds i1, i1* %[[load]], i64 0 +; CHECK: store i1 %[[phi]], i1* %[[gep0]], align 4 + +; CHECK: %[[gep1:.*]] = getelementptr inbounds i1, i1* %[[load]], i64 0 +; CHECK: store i1 %[[phi]], i1* %[[gep1]], align 4 |
