[DA] Fix crash when two loops have different type sizes of becount

[scui-ibm]

The type sizes of backedge taken counts for two loops can be different and this is to fix the crash in haveSameSD (#165014).

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: Shimin Cui (scui-ibm)

Changes

The type sizes of backedge taken counts for two loops can be different and this is to fix the crash in haveSameSD (#165014).

---

Full diff: https://github.com/llvm/llvm-project/pull/165021.diff

2 Files Affected:

• (modified) llvm/lib/Analysis/DependenceAnalysis.cpp (+12-3)
• (added) llvm/test/Analysis/DependenceAnalysis/same-sd-for-diff-becount-type-loops.ll (+68)

diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp index a572eefddd20e..3e9b9ee77640f 100644 --- a/llvm/lib/Analysis/DependenceAnalysis.cpp +++ b/llvm/lib/Analysis/DependenceAnalysis.cpp @@ -1131,9 +1131,18 @@ bool DependenceInfo::haveSameSD(const Loop *SrcLoop, if (SE->hasLoopInvariantBackedgeTakenCount(DstLoop)) DstUP = SE->getBackedgeTakenCount(DstLoop); - if (SrcUB != nullptr && DstUP != nullptr && - SE->isKnownPredicate(ICmpInst::ICMP_EQ, SrcUB, DstUP)) - return true; + if (SrcUB != nullptr && DstUP != nullptr) { + unsigned SrcBitWidth = SE->getTypeSizeInBits(SrcUB->getType()); + unsigned DstBitWidth = SE->getTypeSizeInBits(DstUP->getType()); + if (SrcBitWidth < DstBitWidth) { + SrcUB = SE->getZeroExtendExpr(SrcUB, DstUP->getType()); + } else if (SrcBitWidth > DstBitWidth) { + DstUP = SE->getZeroExtendExpr(DstUP, SrcUB->getType()); + } + + if (SE->isKnownPredicate(ICmpInst::ICMP_EQ, SrcUB, DstUP)) + return true; + } return false; } diff --git a/llvm/test/Analysis/DependenceAnalysis/same-sd-for-diff-becount-type-loops.ll b/llvm/test/Analysis/DependenceAnalysis/same-sd-for-diff-becount-type-loops.ll new file mode 100644 index 0000000000000..66880b5a553ec --- /dev/null +++ b/llvm/test/Analysis/DependenceAnalysis/same-sd-for-diff-becount-type-loops.ll @@ -0,0 +1,68 @@ +; RUN: opt < %s -disable-output "-passes=print<da>" -aa-pipeline=basic-aa 2>&1 | FileCheck %s + +define void @f1() { +; CHECK-LABEL: 'f1' +; CHECK-NEXT: Src: store i32 0, ptr null, align 4 --> Dst: store i32 0, ptr null, align 4 +; CHECK-NEXT: da analyze - consistent output [S]! +; CHECK-NEXT: Src: store i32 0, ptr null, align 4 --> Dst: %2 = load i32, ptr null, align 4 +; CHECK-NEXT: da analyze - consistent flow [|<]! +; CHECK-NEXT: Src: %2 = load i32, ptr null, align 4 --> Dst: %2 = load i32, ptr null, align 4 +; CHECK-NEXT: da analyze - consistent input [S]! +; +entry: + br label %for.1.header + +for.1.header: ; preds = %for.2.end, %entry + br label %for.1.body + +for.1.body: ; preds = %for.1.body, %whiledo + %0 = phi i32 [ 0, %for.1.header ], [ 1, %for.1.body ] + store i32 0, ptr null, align 4 + %1 = icmp ult i32 %0, 1 + br i1 %1, label %for.1.body, label %for.1.end + +for.1.end: ; preds = %for.1.body + br label %for.2.body + +for.2.body: ; preds = %for.2.body, %for.1.end + %2 = load i32, ptr null, align 4 + br i1 false, label %for.2.body, label %exit + +exit: ; preds = %for.2.body + ret void +} + +define void @f2() { +; CHECK-LABEL: 'f2' +; CHECK-NEXT: Src: store i32 0, ptr null, align 4 --> Dst: store i32 0, ptr null, align 4 +; CHECK-NEXT: da analyze - consistent output [S]! +; CHECK-NEXT: Src: store i32 0, ptr null, align 4 --> Dst: %3 = load i32, ptr null, align 4 +; CHECK-NEXT: da analyze - flow [|<] / assuming 1 loop level(s) fused: [S|<]! +; CHECK-NEXT: Src: %3 = load i32, ptr null, align 4 --> Dst: %3 = load i32, ptr null, align 4 +; CHECK-NEXT: da analyze - consistent input [S]! +; +entry: + br label %for.1.header + +for.1.header: ; preds = %for.2.end, %entry + br label %for.1.body + +for.1.body: ; preds = %for.1.body, %whiledo + %0 = phi i32 [ 0, %for.1.header ], [ 1, %for.1.body ] + store i32 0, ptr null, align 4 + %1 = icmp ult i32 %0, 1 + br i1 %1, label %for.1.body, label %for.1.end + +for.1.end: ; preds = %for.1.body + br label %for.2.body + +for.2.body: ; preds = %for.2.body, %for.1.end + %2 = phi i64 [ 0, %for.1.end ], [ %4, %for.2.body ] + %3 = load i32, ptr null, align 4 + %4 = add nuw nsw i64 %2, 1 + %5 = icmp ult i64 %4, 2 + br i1 %5, label %for.2.body, label %exit + +exit: ; preds = %for.2.body + ret void +} 

[fhahn]

Could use SE.getWiderType/getNoopOrZeroExtend