From acb56090639de1413b0147c66f78698844f37114 Mon Sep 17 00:00:00 2001
From: Joseph Tremoulet <jotrem@microsoft.com>
Date: Wed, 5 Jun 2019 21:30:10 +0000
Subject: [PATCH] [EarlyCSE] Add tests for negated min/max/abs [NFC]

Summary:
I'm planning to update the hashing logic to recognize their equivalence
in a subsequent change (D62644).

Reviewers: spatel

Reviewed By: spatel

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62918

llvm-svn: 362657
---
 llvm/test/Transforms/EarlyCSE/commute.ll | 102 +++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)

diff --git a/llvm/test/Transforms/EarlyCSE/commute.ll b/llvm/test/Transforms/EarlyCSE/commute.ll
index 488acf6..32dd55b 100644
--- a/llvm/test/Transforms/EarlyCSE/commute.ll
+++ b/llvm/test/Transforms/EarlyCSE/commute.ll
@@ -107,6 +107,24 @@ define i1 @smin_swapped(i8 %a, i8 %b) {
   ret i1 %r
 }
 
+; Min/max can also have an inverted predicate and select operands.
+; TODO: Ensure we always recognize this (currently depends on hash collision)
+
+define i1 @smin_inverted(i8 %a, i8 %b) {
+; CHECK-LABEL: @smin_inverted(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i8 [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[CMP2:%.*]] = xor i1 [[CMP1]], true
+; CHECK-NEXT:    [[M1:%.*]] = select i1 [[CMP1]], i8 [[A]], i8 [[B]]
+; CHECK:         ret i1
+;
+  %cmp1 = icmp slt i8 %a, %b
+  %cmp2 = xor i1 %cmp1, -1
+  %m1 = select i1 %cmp1, i8 %a, i8 %b
+  %m2 = select i1 %cmp2, i8 %b, i8 %a
+  %r = icmp eq i8 %m1, %m2
+  ret i1 %r
+}
+
 define i8 @smax_commute(i8 %a, i8 %b) {
 ; CHECK-LABEL: @smax_commute(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt i8 [[A:%.*]], [[B:%.*]]
@@ -137,6 +155,22 @@ define i8 @smax_swapped(i8 %a, i8 %b) {
   ret i8 %r
 }
 
+; TODO: Ensure we always recognize this (currently depends on hash collision)
+define i1 @smax_inverted(i8 %a, i8 %b) {
+; CHECK-LABEL: @smax_inverted(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt i8 [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[CMP2:%.*]] = xor i1 [[CMP1]], true
+; CHECK-NEXT:    [[M1:%.*]] = select i1 [[CMP1]], i8 [[A]], i8 [[B]]
+; CHECK:         ret i1
+;
+  %cmp1 = icmp sgt i8 %a, %b
+  %cmp2 = xor i1 %cmp1, -1
+  %m1 = select i1 %cmp1, i8 %a, i8 %b
+  %m2 = select i1 %cmp2, i8 %b, i8 %a
+  %r = icmp eq i8 %m1, %m2
+  ret i1 %r
+}
+
 define i8 @umin_commute(i8 %a, i8 %b) {
 ; CHECK-LABEL: @umin_commute(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i8 [[A:%.*]], [[B:%.*]]
@@ -169,6 +203,22 @@ define <2 x i8> @umin_swapped(<2 x i8> %a, <2 x i8> %b) {
   ret <2 x i8> %r
 }
 
+; TODO: Ensure we always recognize this (currently depends on hash collision)
+define i1 @umin_inverted(i8 %a, i8 %b) {
+; CHECK-LABEL: @umin_inverted(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i8 [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[CMP2:%.*]] = xor i1 [[CMP1]], true
+; CHECK-NEXT:    [[M1:%.*]] = select i1 [[CMP1]], i8 [[A]], i8 [[B]]
+; CHECK:         ret i1
+;
+  %cmp1 = icmp ult i8 %a, %b
+  %cmp2 = xor i1 %cmp1, -1
+  %m1 = select i1 %cmp1, i8 %a, i8 %b
+  %m2 = select i1 %cmp2, i8 %b, i8 %a
+  %r = icmp eq i8 %m1, %m2
+  ret i1 %r
+}
+
 define i8 @umax_commute(i8 %a, i8 %b) {
 ; CHECK-LABEL: @umax_commute(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i8 [[A:%.*]], [[B:%.*]]
@@ -200,6 +250,22 @@ define i8 @umax_swapped(i8 %a, i8 %b) {
   ret i8 %r
 }
 
+; TODO: Ensure we always recognize this (currently depends on hash collision)
+define i1 @umax_inverted(i8 %a, i8 %b) {
+; CHECK-LABEL: @umax_inverted(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i8 [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[CMP2:%.*]] = xor i1 [[CMP1]], true
+; CHECK-NEXT:    [[M1:%.*]] = select i1 [[CMP1]], i8 [[A]], i8 [[B]]
+; CHECK:         ret i1
+;
+  %cmp1 = icmp ugt i8 %a, %b
+  %cmp2 = xor i1 %cmp1, -1
+  %m1 = select i1 %cmp1, i8 %a, i8 %b
+  %m2 = select i1 %cmp2, i8 %b, i8 %a
+  %r = icmp eq i8 %m1, %m2
+  ret i1 %r
+}
+
 ; Min/max may exist with non-canonical operands. Value tracking can match those.
 
 define i8 @smax_nsw(i8 %a, i8 %b) {
@@ -236,6 +302,24 @@ define i8 @abs_swapped(i8 %a) {
   ret i8 %r
 }
 
+; TODO: Ensure we always recognize this (currently depends on hash collision)
+define i8 @abs_inverted(i8 %a) {
+; CHECK-LABEL: @abs_inverted(
+; CHECK-NEXT:    [[NEG:%.*]] = sub i8 0, [[A:%.*]]
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt i8 [[A]], 0
+; CHECK-NEXT:    [[CMP2:%.*]] = xor i1 [[CMP1]], true
+; CHECK-NEXT:    [[M1:%.*]] = select i1 [[CMP1]], i8 [[A]], i8 [[NEG]]
+; CHECK:         ret i8
+;
+  %neg = sub i8 0, %a
+  %cmp1 = icmp sgt i8 %a, 0
+  %cmp2 = xor i1 %cmp1, -1
+  %m1 = select i1 %cmp1, i8 %a, i8 %neg
+  %m2 = select i1 %cmp2, i8 %neg, i8 %a
+  %r = or i8 %m2, %m1
+  ret i8 %r
+}
+
 define i8 @nabs_swapped(i8 %a) {
 ; CHECK-LABEL: @nabs_swapped(
 ; CHECK-NEXT:    [[NEG:%.*]] = sub i8 0, [[A:%.*]]
@@ -253,6 +337,24 @@ define i8 @nabs_swapped(i8 %a) {
   ret i8 %r
 }
 
+; TODO: Ensure we always recognize this (currently depends on hash collision)
+define i8 @nabs_inverted(i8 %a) {
+; CHECK-LABEL: @nabs_inverted(
+; CHECK-NEXT:    [[NEG:%.*]] = sub i8 0, [[A:%.*]]
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i8 [[A]], 0
+; CHECK-NEXT:    [[CMP2:%.*]] = xor i1 [[CMP1]], true
+; CHECK-NEXT:    [[M1:%.*]] = select i1 [[CMP1]], i8 [[A]], i8 [[NEG]]
+; CHECK:         ret i8
+;
+  %neg = sub i8 0, %a
+  %cmp1 = icmp slt i8 %a, 0
+  %cmp2 = xor i1 %cmp1, -1
+  %m1 = select i1 %cmp1, i8 %a, i8 %neg
+  %m2 = select i1 %cmp2, i8 %neg, i8 %a
+  %r = xor i8 %m2, %m1
+  ret i8 %r
+}
+
 ; These two tests make sure we still consider it a match when the RHS of the
 ; compares are different.
 define i8 @abs_different_constants(i8 %a) {
-- 
2.7.4