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| -rw-r--r-- | llvm/test/Transforms/SimplifyCFG/safe-abs.ll | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/llvm/test/Transforms/SimplifyCFG/safe-abs.ll b/llvm/test/Transforms/SimplifyCFG/safe-abs.ll new file mode 100644 index 00000000000..550fcefdde3 --- /dev/null +++ b/llvm/test/Transforms/SimplifyCFG/safe-abs.ll @@ -0,0 +1,34 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -simplifycfg -S | FileCheck %s + +; Reduced from arm_abs_q31() from CMSIS DSP suite. +; https://reviews.llvm.org/D65148#1629010 + +define i32 @abs_with_clamp(i32 %arg) { +; CHECK-LABEL: @abs_with_clamp( +; CHECK-NEXT: begin: +; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[ARG:%.*]], 0 +; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[END:%.*]], label [[NEGATIVE:%.*]] +; CHECK: negative: +; CHECK-NEXT: [[IS_INT_MIN:%.*]] = icmp eq i32 [[ARG]], -2147483648 +; CHECK-NEXT: [[NEGATED:%.*]] = sub nsw i32 0, [[ARG]] +; CHECK-NEXT: [[ABS:%.*]] = select i1 [[IS_INT_MIN]], i32 2147483647, i32 [[NEGATED]] +; CHECK-NEXT: br label [[END]] +; CHECK: end: +; CHECK-NEXT: [[TMP6:%.*]] = phi i32 [ [[ARG]], [[BEGIN:%.*]] ], [ [[ABS]], [[NEGATIVE]] ] +; CHECK-NEXT: ret i32 [[TMP6]] +; +begin: + %is_positive = icmp sgt i32 %arg, 0 + br i1 %is_positive, label %end, label %negative + +negative: ; preds = %begin + %is_int_min = icmp eq i32 %arg, -2147483648 + %negated = sub nsw i32 0, %arg + %abs = select i1 %is_int_min, i32 2147483647, i32 %negated + br label %end + +end: ; preds = %negative, %begin + %tmp6 = phi i32 [ %arg, %begin ], [ %abs, %negative ] + ret i32 %tmp6 +} |
