diff options
5 files changed, 62 insertions, 6 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp index ec8b0d42626..77f035a5a65 100644 --- a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp @@ -262,6 +262,10 @@ void SimplifyIndvar::eliminateIVComparison(ICmpInst *ICmp, Value *IVOperand) { ICmp->setPredicate(InvariantPredicate); ICmp->setOperand(0, NewLHS); ICmp->setOperand(1, NewRHS); + } else if (ICmpInst::isSigned(Pred) && + SE->isKnownNonNegative(S) && SE->isKnownNonNegative(X)) { + DEBUG(dbgs() << "INDVARS: Turn to unsigned comparison: " << *ICmp << '\n'); + ICmp->setPredicate(ICmpInst::getUnsignedPredicate(Pred)); } else return; diff --git a/llvm/test/Analysis/ScalarEvolution/guards.ll b/llvm/test/Analysis/ScalarEvolution/guards.ll index 52ad4dc73d4..d4b1f431ffc 100644 --- a/llvm/test/Analysis/ScalarEvolution/guards.ll +++ b/llvm/test/Analysis/ScalarEvolution/guards.ll @@ -19,7 +19,7 @@ entry: loop: ; CHECK: loop: ; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 true) [ "deopt"() ] -; CHECK: %iv.inc.cmp = icmp slt i32 %iv.inc, %len +; CHECK: %iv.inc.cmp = icmp ult i32 %iv.inc, %len ; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %iv.inc.cmp) [ "deopt"() ] ; CHECK: leave: @@ -41,7 +41,7 @@ leave: define void @test_2(i32 %n, i32* %len_buf) { ; CHECK-LABEL: @test_2( -; CHECK: [[LEN_SEXT:%[^ ]+]] = sext i32 %len to i64 +; CHECK: [[LEN_ZEXT:%[^ ]+]] = zext i32 %len to i64 ; CHECK: br label %loop entry: @@ -52,7 +52,7 @@ loop: ; CHECK: loop: ; CHECK: %indvars.iv = phi i64 [ %indvars.iv.next, %loop ], [ 0, %entry ] ; CHECK: %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 -; CHECK: %iv.inc.cmp = icmp slt i64 %indvars.iv.next, [[LEN_SEXT]] +; CHECK: %iv.inc.cmp = icmp ult i64 %indvars.iv.next, [[LEN_ZEXT]] ; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %iv.inc.cmp) [ "deopt"() ] ; CHECK: leave: diff --git a/llvm/test/Transforms/IndVarSimplify/canonicalize-cmp.ll b/llvm/test/Transforms/IndVarSimplify/canonicalize-cmp.ll new file mode 100644 index 00000000000..93dc968af6a --- /dev/null +++ b/llvm/test/Transforms/IndVarSimplify/canonicalize-cmp.ll @@ -0,0 +1,52 @@ +; RUN: opt -S -indvars < %s | FileCheck %s + +; Check that we replace signed comparisons between non-negative values with +; unsigned comparisons if we can. + +target datalayout = "n8:16:32:64" + +define i32 @test_01(i32 %a, i32 %b, i32* %p) { + +; CHECK-LABEL: @test_01( +; CHECK-NOT: icmp slt +; CHECK: %cmp1 = icmp ult i32 %iv, 100 +; CHECK: %cmp2 = icmp ult i32 %iv, 100 +; CHECK-NOT: %cmp3 +; CHECK: %exitcond = icmp ne i32 %iv.next, 1000 + +entry: + br label %loop.entry + +loop.entry: + %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.be ] + %cmp1 = icmp slt i32 %iv, 100 + br i1 %cmp1, label %b1, label %b2 + +b1: + store i32 %iv, i32* %p + br label %merge + +b2: + store i32 %a, i32* %p + br label %merge + +merge: + %cmp2 = icmp ult i32 %iv, 100 + br i1 %cmp2, label %b3, label %b4 + +b3: + store i32 %iv, i32* %p + br label %loop.be + +b4: + store i32 %b, i32* %p + br label %loop.be + +loop.be: + %iv.next = add i32 %iv, 1 + %cmp3 = icmp slt i32 %iv.next, 1000 + br i1 %cmp3, label %loop.entry, label %exit + +exit: + ret i32 %iv +} diff --git a/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll b/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll index 612f01e3cad..a63617e62c0 100644 --- a/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll +++ b/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll @@ -111,7 +111,7 @@ return: ; Indvars should not turn the second loop into an infinite one. ; CHECK-LABEL: @func_11( -; CHECK: %tmp5 = icmp slt i32 %__key6.0, 10 +; CHECK: %tmp5 = icmp ult i32 %__key6.0, 10 ; CHECK-NOT: br i1 true, label %noassert68, label %unrolledend define i32 @func_11() nounwind uwtable { @@ -163,7 +163,7 @@ declare void @llvm.trap() noreturn nounwind ; In this case the second loop only has a single iteration, fold the header away ; CHECK-LABEL: @func_12( -; CHECK: %tmp5 = icmp slt i32 %__key6.0, 10 +; CHECK: %tmp5 = icmp ult i32 %__key6.0, 10 ; CHECK: br i1 true, label %noassert68, label %unrolledend define i32 @func_12() nounwind uwtable { entry: diff --git a/llvm/test/Transforms/IndVarSimplify/widen-loop-comp.ll b/llvm/test/Transforms/IndVarSimplify/widen-loop-comp.ll index b87cd055019..2d24cd732ce 100644 --- a/llvm/test/Transforms/IndVarSimplify/widen-loop-comp.ll +++ b/llvm/test/Transforms/IndVarSimplify/widen-loop-comp.ll @@ -64,7 +64,7 @@ for.end: ; CHECK-LABEL: @test2 ; CHECK: for.body4.us ; CHECK: %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 -; CHECK: %cmp2.us = icmp slt i64 +; CHECK: %cmp2.us = icmp ult i64 ; CHECK-NOT: %2 = trunc i64 %indvars.iv.next to i32 ; CHECK-NOT: %cmp2.us = icmp slt i32 |
