diff --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp index 277f530ee25fc..0ea8244924c0f 100644 --- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp +++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp @@ -123,6 +123,13 @@ static bool populateDependencyMatrix(CharMatrix &DepMatrix, unsigned Level, // Track Output, Flow, and Anti dependencies. if (auto D = DI->depends(Src, Dst, true)) { assert(D->isOrdered() && "Expected an output, flow or anti dep."); + + if (D->isConfused()) { + LLVM_DEBUG(dbgs() << " Confused dependency between:\n" + << " " << *Src << "\n" + << " " << *Dst << "\n"); + return false; + } // If the direction vector is negative, normalize it to // make it non-negative. if (D->normalize(SE)) diff --git a/llvm/test/Transforms/LoopInterchange/lcssa.ll b/llvm/test/Transforms/LoopInterchange/lcssa.ll index b41eba4ef5617..d3a0675caa799 100644 --- a/llvm/test/Transforms/LoopInterchange/lcssa.ll +++ b/llvm/test/Transforms/LoopInterchange/lcssa.ll @@ -180,7 +180,7 @@ for.end16: ; preds = %for.exit ; REMARK: Interchanged ; REMARK-NEXT: lcssa_05 -define void @lcssa_05(ptr %ptr) { +define void @lcssa_05(ptr noalias %ptr) { entry: br label %outer.header @@ -225,7 +225,7 @@ for.end16: ; preds = %for.exit ; REMARK: UnsupportedExitPHI ; REMARK-NEXT: lcssa_06 -define void @lcssa_06(ptr %ptr, ptr %ptr1) { +define void @lcssa_06(ptr %ptr, ptr noalias %ptr1) { entry: br label %outer.header diff --git a/llvm/test/Transforms/LoopInterchange/pr43326-ideal-access-pattern.ll b/llvm/test/Transforms/LoopInterchange/pr43326-ideal-access-pattern.ll index def68ca3cd07e..3b31c2634be71 100644 --- a/llvm/test/Transforms/LoopInterchange/pr43326-ideal-access-pattern.ll +++ b/llvm/test/Transforms/LoopInterchange/pr43326-ideal-access-pattern.ll @@ -27,7 +27,7 @@ ; REMARKS-NEXT: Name: Interchanged ; REMARKS-NEXT: Function: pr43326-triply-nested -define void @pr43326-triply-nested(ptr %e, ptr %f) { +define void @pr43326-triply-nested(ptr noalias %e, ptr %f) { entry: br label %for.outermost.header diff --git a/llvm/test/Transforms/LoopInterchange/pr47259.ll b/llvm/test/Transforms/LoopInterchange/pr47259.ll new file mode 100644 index 0000000000000..2a365a62795f8 --- /dev/null +++ b/llvm/test/Transforms/LoopInterchange/pr47259.ll @@ -0,0 +1,55 @@ +; REQUIRES: asserts +; RUN: opt < %s -passes=loop-interchange -cache-line-size=64 -verify-dom-info -verify-loop-info \ +; RUN: -S -debug 2>&1 | FileCheck %s + +;; Test that a confused dependency in loop should prevent interchange in +;; loops i and j. +;; +;; void test_deps() { +;; for (int i = 0; i <= 3; i++) +;; for (int j = 0; j <= 3; j++) { +;; *f ^= 0x1000; +;; c[j][i] = *f; +;; } +;; } + + +; CHECK: Confused dependency between: +; CHECK: store i32 %xor, ptr %arrayidx6, align 4 +; CHECK: %1 = load i32, ptr %0, align 4 +; CHECK-NOT: Loops interchanged. + +@a = global i32 0, align 4 +@f = global ptr @a, align 8 +@c = global [4 x [4 x i32]] zeroinitializer, align 8 + +define void @test_deps() { +entry: + %0 = load ptr, ptr @f, align 8 + br label %for.cond1.preheader + +; Loop: +for.cond1.preheader: ; preds = %entry, %for.cond.cleanup3 + %indvars.iv16 = phi i64 [ 0, %entry ], [ %indvars.iv.next17, %for.cond.cleanup3 ] + br label %for.body4 + +for.cond.cleanup3: ; preds = %for.body4 + %indvars.iv.next17 = add nuw nsw i64 %indvars.iv16, 1 + %exitcond18 = icmp ne i64 %indvars.iv.next17, 4 + br i1 %exitcond18, label %for.cond1.preheader, label %for.cond.cleanup + +for.body4: ; preds = %for.cond1.preheader, %for.body4 + %indvars.iv = phi i64 [ 0, %for.cond1.preheader ], [ %indvars.iv.next, %for.body4 ] + %1 = load i32, ptr %0, align 4 + %xor = xor i32 %1, 4096 + store i32 %xor, ptr %0, align 4 + %arrayidx6 = getelementptr inbounds [4 x [4 x i32]], ptr @c, i64 0, i64 %indvars.iv, i64 %indvars.iv16 + store i32 %xor, ptr %arrayidx6, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp ne i64 %indvars.iv.next, 4 + br i1 %exitcond, label %for.body4, label %for.cond.cleanup3 + +; Exit blocks +for.cond.cleanup: ; preds = %for.cond.cleanup3 + ret void +} diff --git a/llvm/test/Transforms/LoopInterchange/reductions-across-inner-and-outer-loop.ll b/llvm/test/Transforms/LoopInterchange/reductions-across-inner-and-outer-loop.ll index fa2021a15a080..40cf1e9623b8c 100644 --- a/llvm/test/Transforms/LoopInterchange/reductions-across-inner-and-outer-loop.ll +++ b/llvm/test/Transforms/LoopInterchange/reductions-across-inner-and-outer-loop.ll @@ -156,7 +156,7 @@ for1.loopexit: ; preds = %for1.inc ; REMARKS-NEXT: Name: UnsupportedPHIOuter ; REMARKS-NEXT: Function: test4 -define i64 @test4(ptr %Arr, ptr %dst) { +define i64 @test4(ptr %Arr, ptr noalias %dst) { entry: %gep.dst = getelementptr inbounds i64, ptr %dst, i64 42 br label %for1.header @@ -234,7 +234,7 @@ for1.loopexit: ; preds = %for1.inc ; REMARKS-NEXT: Name: Interchanged ; REMARKS-NEXT: Function: test5 -define float @test5(ptr %Arr, ptr %Arr2) { +define float @test5(ptr %Arr, ptr noalias %Arr2) { entry: br label %outer.header @@ -274,7 +274,7 @@ for.exit: ; preds = %outer.inc ; REMARKS-NEXT: Name: UnsupportedPHIOuter ; REMARKS-NEXT: Function: test6 -define float @test6(ptr %Arr, ptr %Arr2) { +define float @test6(ptr %Arr, ptr noalias %Arr2) { entry: br label %outer.header diff --git a/llvm/test/Transforms/LoopInterchange/vector-gep-operand.ll b/llvm/test/Transforms/LoopInterchange/vector-gep-operand.ll index 03e3b4b7408b5..b4f9d3f2a3685 100644 --- a/llvm/test/Transforms/LoopInterchange/vector-gep-operand.ll +++ b/llvm/test/Transforms/LoopInterchange/vector-gep-operand.ll @@ -6,35 +6,25 @@ define void @test(ptr noalias %src, ptr %dst) { ; CHECK-LABEL: @test( ; CHECK-NEXT: entry: -; CHECK-NEXT: br label [[INNER_PREHEADER:%.*]] -; CHECK: outer.header.preheader: ; CHECK-NEXT: br label [[OUTER_HEADER:%.*]] ; CHECK: outer.header: -; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[OUTER_LATCH:%.*]] ], [ 0, [[OUTER_HEADER_PREHEADER:%.*]] ] -; CHECK-NEXT: br label [[INNER_SPLIT1:%.*]] -; CHECK: inner.preheader: +; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[OUTER_LATCH:%.*]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: br label [[INNER:%.*]] ; CHECK: inner: -; CHECK-NEXT: [[J:%.*]] = phi i64 [ [[TMP0:%.*]], [[INNER_SPLIT:%.*]] ], [ 0, [[INNER_PREHEADER]] ] -; CHECK-NEXT: br label [[OUTER_HEADER_PREHEADER]] -; CHECK: inner.split1: +; CHECK-NEXT: [[J:%.*]] = phi i64 [ 0, [[OUTER_HEADER]] ], [ [[J_NEXT:%.*]], [[INNER]] ] ; CHECK-NEXT: [[SRC_GEP:%.*]] = getelementptr inbounds [256 x float], ptr [[SRC:%.*]], <2 x i64> , i64 [[J]] ; CHECK-NEXT: [[SRC_0:%.*]] = extractelement <2 x ptr> [[SRC_GEP]], i32 0 ; CHECK-NEXT: [[LV_0:%.*]] = load float, ptr [[SRC_0]], align 4 ; CHECK-NEXT: [[ADD_0:%.*]] = fadd float [[LV_0]], 1.000000e+00 ; CHECK-NEXT: [[DST_GEP:%.*]] = getelementptr inbounds float, ptr [[DST:%.*]], i64 [[J]] ; CHECK-NEXT: store float [[ADD_0]], ptr [[DST_GEP]], align 4 -; CHECK-NEXT: [[J_NEXT:%.*]] = add nuw nsw i64 [[J]], 1 +; CHECK-NEXT: [[J_NEXT]] = add nuw nsw i64 [[J]], 1 ; CHECK-NEXT: [[INNER_EXITCOND:%.*]] = icmp eq i64 [[J_NEXT]], 100 -; CHECK-NEXT: br label [[OUTER_LATCH]] -; CHECK: inner.split: -; CHECK-NEXT: [[TMP0]] = add nuw nsw i64 [[J]], 1 -; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 100 -; CHECK-NEXT: br i1 [[TMP1]], label [[EXIT:%.*]], label [[INNER]] +; CHECK-NEXT: br i1 [[INNER_EXITCOND]], label [[OUTER_LATCH]], label [[INNER]] ; CHECK: outer.latch: ; CHECK-NEXT: [[I_NEXT]] = add nuw nsw i32 [[I]], 1 ; CHECK-NEXT: [[OUTER_EXITCOND:%.*]] = icmp eq i32 [[I_NEXT]], 100 -; CHECK-NEXT: br i1 [[OUTER_EXITCOND]], label [[INNER_SPLIT]], label [[OUTER_HEADER]] +; CHECK-NEXT: br i1 [[OUTER_EXITCOND]], label [[EXIT:%.*]], label [[OUTER_HEADER]] ; CHECK: exit: ; CHECK-NEXT: ret void ;