diff --git a/llvm/test/Transforms/LoopPredication/poison.ll b/llvm/test/Transforms/LoopPredication/poison.ll new file mode 100644 index 0000000000000..886ec090a0216 --- /dev/null +++ b/llvm/test/Transforms/LoopPredication/poison.ll @@ -0,0 +1,111 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -S -passes=loop-predication < %s 2>&1 | FileCheck %s +; RUN: opt -S -passes='require,loop-mssa(loop-predication)' -verify-memoryssa < %s 2>&1 | FileCheck %s + +declare void @llvm.experimental.guard(i1, ...) + +; Check the case when N on latch exit might be poison. +define i32 @test1(i32 %length, i32 %nlimit) { +; CHECK-LABEL: @test1( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[M:%.*]] = add nuw nsw i32 [[NLIMIT:%.*]], 2 +; CHECK-NEXT: [[N:%.*]] = xor i32 [[M]], 1 +; CHECK-NEXT: [[TMP0:%.*]] = icmp ule i32 [[N]], [[LENGTH:%.*]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i32 0, [[LENGTH]] +; CHECK-NEXT: [[TMP2:%.*]] = and i1 [[TMP1]], [[TMP0]] +; CHECK-NEXT: br label [[LOOP:%.*]] +; CHECK: loop: +; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[OK:%.*]] ], [ 0, [[ENTRY:%.*]] ] +; CHECK-NEXT: [[J:%.*]] = phi i32 [ [[J_NEXT:%.*]], [[OK]] ], [ 0, [[ENTRY]] ] +; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[J]], [[LENGTH]] +; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP2]], i32 9) [ "deopt"() ] +; CHECK-NEXT: call void @llvm.assume(i1 [[WITHIN_BOUNDS]]) +; CHECK-NEXT: [[TMP:%.*]] = icmp ult i32 [[NLIMIT]], 1000 +; CHECK-NEXT: br i1 [[TMP]], label [[OK]], label [[EXIT:%.*]] +; CHECK: ok: +; CHECK-NEXT: [[I_NEXT]] = add i32 [[I]], 1 +; CHECK-NEXT: [[J_NEXT]] = add i32 [[J]], 1 +; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N]] +; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT]] +; CHECK: exit: +; CHECK-NEXT: ret i32 0 +; +entry: + ; %n might be a poison. + %m = add nuw nsw i32 %nlimit, 2 + %n = xor i32 %m, 1 + br label %loop + +loop: + %i = phi i32 [ %i.next, %ok ], [ 0, %entry ] + %j = phi i32 [ %j.next, %ok ], [ 0, %entry ] + %within.bounds = icmp ult i32 %j, %length + call void (i1, ...) @llvm.experimental.guard(i1 %within.bounds, i32 9) [ "deopt"() ] + + ; This check guarantees %n is not a posion. + %tmp = icmp ult i32 %nlimit, 1000 + br i1 %tmp, label %ok, label %exit + +ok: + %i.next = add i32 %i, 1 + %j.next = add i32 %j, 1 + %continue = icmp ult i32 %i.next, %n + br i1 %continue, label %loop, label %exit + +exit: + ret i32 0 +} + + +; Check the case when start value of IV might be a poison. +define i32 @test2(i32 noundef %length, i32 noundef %nlimit, i32 %istart) { +; CHECK-LABEL: @test2( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[M:%.*]] = add nuw nsw i32 [[ISTART:%.*]], 2 +; CHECK-NEXT: [[ISTART2:%.*]] = xor i32 [[M]], 1 +; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[ISTART2]], [[LENGTH:%.*]] +; CHECK-NEXT: [[TMP1:%.*]] = add i32 [[TMP0]], -1 +; CHECK-NEXT: [[TMP2:%.*]] = icmp ule i32 [[NLIMIT:%.*]], [[TMP1]] +; CHECK-NEXT: [[TMP3:%.*]] = icmp ult i32 1, [[LENGTH]] +; CHECK-NEXT: [[TMP4:%.*]] = and i1 [[TMP3]], [[TMP2]] +; CHECK-NEXT: br label [[LOOP:%.*]] +; CHECK: loop: +; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[OK:%.*]] ], [ [[ISTART2]], [[ENTRY:%.*]] ] +; CHECK-NEXT: [[J:%.*]] = phi i32 [ [[J_NEXT:%.*]], [[OK]] ], [ 1, [[ENTRY]] ] +; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[J]], [[LENGTH]] +; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP4]], i32 9) [ "deopt"() ] +; CHECK-NEXT: call void @llvm.assume(i1 [[WITHIN_BOUNDS]]) +; CHECK-NEXT: [[TMP:%.*]] = icmp ult i32 [[ISTART]], 1000 +; CHECK-NEXT: br i1 [[TMP]], label [[OK]], label [[EXIT:%.*]] +; CHECK: ok: +; CHECK-NEXT: [[I_NEXT]] = add i32 [[I]], 1 +; CHECK-NEXT: [[J_NEXT]] = add i32 [[J]], 1 +; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[NLIMIT]] +; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT]] +; CHECK: exit: +; CHECK-NEXT: ret i32 0 +; +entry: + ; %m might be a poison. + %m = add nuw nsw i32 %istart, 2 + %istart2 = xor i32 %m, 1 + br label %loop + +loop: + %i = phi i32 [ %i.next, %ok ], [ %istart2, %entry ] + %j = phi i32 [ %j.next, %ok ], [ 1, %entry ] + %within.bounds = icmp ult i32 %j, %length + call void (i1, ...) @llvm.experimental.guard(i1 %within.bounds, i32 9) [ "deopt"() ] + ; This check guarantees %n is not a posion. + %tmp = icmp ult i32 %istart, 1000 + br i1 %tmp, label %ok, label %exit + +ok: + %i.next = add i32 %i, 1 + %j.next = add i32 %j, 1 + %continue = icmp ult i32 %i.next, %nlimit + br i1 %continue, label %loop, label %exit + +exit: + ret i32 0 +}