From 0f3e255ab829e1e215e6df30211f44c724cc8307 Mon Sep 17 00:00:00 2001 From: Roman Lebedev Date: Mon, 1 Jul 2019 12:22:06 +0000 Subject: [PATCH] [NFC][InstCombine] Tests for ((~x) + y) + 1 -> y - x fold fold (PR42459) To be noted, this pattern is not unhandled by instcombine per-se, it is somehow does end up being folded when one runs opt -O3, but not if it's just -instcombine. Regardless, that fold is indirect, depends on some other folds, and is thus blind when there are extra uses. https://bugs.llvm.org/show_bug.cgi?id=42459 https://rise4fun.com/Alive/EPO0 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364749 91177308-0d34-0410-b5e6-96231b3b80d8 --- ...ld-inc-of-add-of-not-x-and-y-to-sub-x-from-y.ll | 184 +++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 test/Transforms/InstCombine/fold-inc-of-add-of-not-x-and-y-to-sub-x-from-y.ll diff --git a/test/Transforms/InstCombine/fold-inc-of-add-of-not-x-and-y-to-sub-x-from-y.ll b/test/Transforms/InstCombine/fold-inc-of-add-of-not-x-and-y-to-sub-x-from-y.ll new file mode 100644 index 00000000000..54e3b87df8b --- /dev/null +++ b/test/Transforms/InstCombine/fold-inc-of-add-of-not-x-and-y-to-sub-x-from-y.ll @@ -0,0 +1,184 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -instcombine -S < %s | FileCheck %s + +; Given: +; add (add (xor %x, -1), %y), 1 +; Transform it to: +; sub %y, %x + +;------------------------------------------------------------------------------; +; Scalar tests +;------------------------------------------------------------------------------; + +define i32 @t0(i32 %x, i32 %y) { +; CHECK-LABEL: @t0( +; CHECK-NEXT: [[T0:%.*]] = xor i32 [[X:%.*]], -1 +; CHECK-NEXT: [[T1:%.*]] = add i32 [[T0]], [[Y:%.*]] +; CHECK-NEXT: [[T2:%.*]] = add i32 [[T1]], 1 +; CHECK-NEXT: ret i32 [[T2]] +; + %t0 = xor i32 %x, -1 + %t1 = add i32 %t0, %y + %t2 = add i32 %t1, 1 + ret i32 %t2 +} + +;------------------------------------------------------------------------------; +; Vector tests +;------------------------------------------------------------------------------; + +define <4 x i32> @t1_vec_splat(<4 x i32> %x, <4 x i32> %y) { +; CHECK-LABEL: @t1_vec_splat( +; CHECK-NEXT: [[T0:%.*]] = xor <4 x i32> [[X:%.*]], +; CHECK-NEXT: [[T1:%.*]] = add <4 x i32> [[T0]], [[Y:%.*]] +; CHECK-NEXT: [[T2:%.*]] = add <4 x i32> [[T1]], +; CHECK-NEXT: ret <4 x i32> [[T2]] +; + %t0 = xor <4 x i32> %x, + %t1 = add <4 x i32> %t0, %y + %t2 = add <4 x i32> %t1, + ret <4 x i32> %t2 +} + +define <4 x i32> @t2_vec_undef0(<4 x i32> %x, <4 x i32> %y) { +; CHECK-LABEL: @t2_vec_undef0( +; CHECK-NEXT: [[T0:%.*]] = xor <4 x i32> [[X:%.*]], +; CHECK-NEXT: [[T1:%.*]] = add <4 x i32> [[T0]], [[Y:%.*]] +; CHECK-NEXT: [[T2:%.*]] = add <4 x i32> [[T1]], +; CHECK-NEXT: ret <4 x i32> [[T2]] +; + %t0 = xor <4 x i32> %x, + %t1 = add <4 x i32> %t0, %y + %t2 = add <4 x i32> %t1, + ret <4 x i32> %t2 +} + +define <4 x i32> @t3_vec_undef1(<4 x i32> %x, <4 x i32> %y) { +; CHECK-LABEL: @t3_vec_undef1( +; CHECK-NEXT: [[T0:%.*]] = xor <4 x i32> [[X:%.*]], +; CHECK-NEXT: [[T1:%.*]] = add <4 x i32> [[T0]], [[Y:%.*]] +; CHECK-NEXT: [[T2:%.*]] = add <4 x i32> [[T1]], +; CHECK-NEXT: ret <4 x i32> [[T2]] +; + %t0 = xor <4 x i32> %x, + %t1 = add <4 x i32> %t0, %y + %t2 = add <4 x i32> %t1, + ret <4 x i32> %t2 +} + +define <4 x i32> @t4_vec_undef2(<4 x i32> %x, <4 x i32> %y) { +; CHECK-LABEL: @t4_vec_undef2( +; CHECK-NEXT: [[T0:%.*]] = xor <4 x i32> [[X:%.*]], +; CHECK-NEXT: [[T1:%.*]] = add <4 x i32> [[T0]], [[Y:%.*]] +; CHECK-NEXT: [[T2:%.*]] = add <4 x i32> [[T1]], +; CHECK-NEXT: ret <4 x i32> [[T2]] +; + %t0 = xor <4 x i32> %x, + %t1 = add <4 x i32> %t0, %y + %t2 = add <4 x i32> %t1, + ret <4 x i32> %t2 +} + +;------------------------------------------------------------------------------; +; One-use tests +;------------------------------------------------------------------------------; + +declare void @use32(i32) + +define i32 @t5(i32 %x, i32 %y) { +; CHECK-LABEL: @t5( +; CHECK-NEXT: [[T0:%.*]] = xor i32 [[X:%.*]], -1 +; CHECK-NEXT: call void @use32(i32 [[T0]]) +; CHECK-NEXT: [[T1:%.*]] = add i32 [[T0]], [[Y:%.*]] +; CHECK-NEXT: [[T2:%.*]] = add i32 [[T1]], 1 +; CHECK-NEXT: ret i32 [[T2]] +; + %t0 = xor i32 %x, -1 + call void @use32(i32 %t0) + %t1 = add i32 %t0, %y + %t2 = add i32 %t1, 1 + ret i32 %t2 +} + +define i32 @t6(i32 %x, i32 %y) { +; CHECK-LABEL: @t6( +; CHECK-NEXT: [[T0:%.*]] = xor i32 [[X:%.*]], -1 +; CHECK-NEXT: [[T1:%.*]] = add i32 [[T0]], [[Y:%.*]] +; CHECK-NEXT: call void @use32(i32 [[T1]]) +; CHECK-NEXT: [[T2:%.*]] = add i32 [[T1]], 1 +; CHECK-NEXT: ret i32 [[T2]] +; + %t0 = xor i32 %x, -1 + %t1 = add i32 %t0, %y + call void @use32(i32 %t1) + %t2 = add i32 %t1, 1 + ret i32 %t2 +} + +define i32 @t7(i32 %x, i32 %y) { +; CHECK-LABEL: @t7( +; CHECK-NEXT: [[T0:%.*]] = xor i32 [[X:%.*]], -1 +; CHECK-NEXT: call void @use32(i32 [[T0]]) +; CHECK-NEXT: [[T1:%.*]] = add i32 [[T0]], [[Y:%.*]] +; CHECK-NEXT: call void @use32(i32 [[T1]]) +; CHECK-NEXT: [[T2:%.*]] = add i32 [[T1]], 1 +; CHECK-NEXT: ret i32 [[T2]] +; + %t0 = xor i32 %x, -1 + call void @use32(i32 %t0) + %t1 = add i32 %t0, %y + call void @use32(i32 %t1) + %t2 = add i32 %t1, 1 + ret i32 %t2 +} + +;------------------------------------------------------------------------------; +; Commutativity +;------------------------------------------------------------------------------; + +declare i32 @gen32() + +define i32 @t8_commutative(i32 %x) { +; CHECK-LABEL: @t8_commutative( +; CHECK-NEXT: [[Y:%.*]] = call i32 @gen32() +; CHECK-NEXT: [[T0:%.*]] = xor i32 [[X:%.*]], -1 +; CHECK-NEXT: [[T1:%.*]] = add i32 [[Y]], [[T0]] +; CHECK-NEXT: [[T2:%.*]] = add i32 [[T1]], 1 +; CHECK-NEXT: ret i32 [[T2]] +; + %y = call i32 @gen32() + %t0 = xor i32 %x, -1 + %t1 = add i32 %y, %t0 ; swapped + %t2 = add i32 %t1, 1 + ret i32 %t2 +} + +;------------------------------------------------------------------------------; +; Basic negative tests +;------------------------------------------------------------------------------; + +define i32 @n9(i32 %x, i32 %y) { +; CHECK-LABEL: @n9( +; CHECK-NEXT: [[T0:%.*]] = xor i32 [[X:%.*]], 2147483647 +; CHECK-NEXT: [[T1:%.*]] = add i32 [[T0]], [[Y:%.*]] +; CHECK-NEXT: [[T2:%.*]] = add i32 [[T1]], 1 +; CHECK-NEXT: ret i32 [[T2]] +; + %t0 = xor i32 %x, 2147483647 ; not -1 + %t1 = add i32 %t0, %y + %t2 = add i32 %t1, 1 + ret i32 %t2 +} + +define i32 @n10(i32 %x, i32 %y) { +; CHECK-LABEL: @n10( +; CHECK-NEXT: [[T0:%.*]] = xor i32 [[X:%.*]], -1 +; CHECK-NEXT: [[T1:%.*]] = add i32 [[T0]], [[Y:%.*]] +; CHECK-NEXT: [[T2:%.*]] = add i32 [[T1]], 2 +; CHECK-NEXT: ret i32 [[T2]] +; + %t0 = xor i32 %x, -1 + %t1 = add i32 %t0, %y + %t2 = add i32 %t1, 2 ; not +1 + ret i32 %t2 +} -- 2.11.0