From 6e88276411c69e194c2f89270a18852a85fc79a7 Mon Sep 17 00:00:00 2001 From: Amara Emerson Date: Wed, 24 May 2023 14:46:20 -0700 Subject: [PATCH] Pre-commit a min/max idiom breakage test for D149918 --- .../InstCombine/ashr-icmp-minmax-idiom-break.ll | 23 ++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 llvm/test/Transforms/InstCombine/ashr-icmp-minmax-idiom-break.ll diff --git a/llvm/test/Transforms/InstCombine/ashr-icmp-minmax-idiom-break.ll b/llvm/test/Transforms/InstCombine/ashr-icmp-minmax-idiom-break.ll new file mode 100644 index 0000000..a539b91 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/ashr-icmp-minmax-idiom-break.ll @@ -0,0 +1,23 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2 +; RUN: opt < %s -passes=instcombine -S | FileCheck %s + +; This test is pre-committed to show sub-optimal codegen due to +; min/max idiom breakage. On AArch64, these constants are also expensive to materialize, +; and therefore generate poor code vs maintaining the min/max idiom. + +define i64 @dont_break_minmax_i64(i64 %conv, i64 %conv2) { +; CHECK-LABEL: define i64 @dont_break_minmax_i64 +; CHECK-SAME: (i64 [[CONV:%.*]], i64 [[CONV2:%.*]]) { +; CHECK-NEXT: [[MUL:%.*]] = mul nsw i64 [[CONV]], [[CONV2]] +; CHECK-NEXT: [[SHR:%.*]] = ashr i64 [[MUL]], 4 +; CHECK-NEXT: [[CMP4_I:%.*]] = icmp slt i64 [[MUL]], 5579712 +; CHECK-NEXT: [[SPEC_SELECT_I:%.*]] = select i1 [[CMP4_I]], i64 [[SHR]], i64 348731 +; CHECK-NEXT: ret i64 [[SPEC_SELECT_I]] +; + %mul = mul nsw i64 %conv, %conv2 + %shr = ashr i64 %mul, 4 + %cmp4.i = icmp sgt i64 %shr, 348731 + %switch.i = icmp ult i1 %cmp4.i, true + %spec.select.i = select i1 %switch.i, i64 %shr, i64 348731 + ret i64 %spec.select.i +} -- 2.7.4