From e6cd157407a24f7be1c15dbf949bac98400ff96d Mon Sep 17 00:00:00 2001
From: Sanjay Patel <spatel@rotateright.com>
Date: Tue, 23 Nov 2021 08:55:49 -0500
Subject: [PATCH] [InstCombine] add tests for logical select; NFC

---
 llvm/test/Transforms/InstCombine/logical-select.ll | 55 +++++++++++++++++++++-
 1 file changed, 54 insertions(+), 1 deletion(-)

diff --git a/llvm/test/Transforms/InstCombine/logical-select.ll b/llvm/test/Transforms/InstCombine/logical-select.ll
index 1ec5b30..459e1b1 100644
--- a/llvm/test/Transforms/InstCombine/logical-select.ll
+++ b/llvm/test/Transforms/InstCombine/logical-select.ll
@@ -1,6 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -instcombine -S | FileCheck %s
 
+declare void @use(i8)
 
 define i32 @foo(i32 %a, i32 %b, i32 %c, i32 %d) {
 ; CHECK-LABEL: @foo(
@@ -388,7 +389,7 @@ define i1 @bools_logical(i1 %a, i1 %b, i1 %c) {
   ret i1 %or
 }
 
-; Form a select if we know we can get replace 2 simple logic ops.
+; Form a select if we know we can replace 2 simple logic ops.
 
 define i1 @bools_multi_uses1(i1 %a, i1 %b, i1 %c) {
 ; CHECK-LABEL: @bools_multi_uses1(
@@ -827,3 +828,55 @@ define i64 @bitcast_int_scalar_cond(<2 x i1> %b, i64 %c, i64 %d) {
   %r = or i64 %t11, %t12
   ret i64 %r
 }
+
+; TODO:
+; Peek through bitcasts and sexts to find negated bool condition.
+
+define <1 x i6> @bitcast_sext_cond(<2 x i1> %cmp, <1 x i6> %a, <1 x i6> %b) {
+; CHECK-LABEL: @bitcast_sext_cond(
+; CHECK-NEXT:    [[SEXT:%.*]] = sext <2 x i1> [[CMP:%.*]] to <2 x i3>
+; CHECK-NEXT:    [[BC1:%.*]] = bitcast <2 x i3> [[SEXT]] to <1 x i6>
+; CHECK-NEXT:    [[NEG:%.*]] = xor <2 x i1> [[CMP]], <i1 true, i1 true>
+; CHECK-NEXT:    [[SEXT2:%.*]] = sext <2 x i1> [[NEG]] to <2 x i3>
+; CHECK-NEXT:    [[BC2:%.*]] = bitcast <2 x i3> [[SEXT2]] to <1 x i6>
+; CHECK-NEXT:    [[AND1:%.*]] = and <1 x i6> [[BC1]], [[A:%.*]]
+; CHECK-NEXT:    [[AND2:%.*]] = and <1 x i6> [[BC2]], [[B:%.*]]
+; CHECK-NEXT:    [[OR:%.*]] = or <1 x i6> [[AND1]], [[AND2]]
+; CHECK-NEXT:    ret <1 x i6> [[OR]]
+;
+  %sext = sext <2 x i1> %cmp to <2 x i3>
+  %bc1 = bitcast <2 x i3> %sext to <1 x i6>
+  %neg = xor <2 x i1> %cmp, <i1 -1, i1 -1>
+  %sext2 = sext <2 x i1> %neg to <2 x i3>
+  %bc2 = bitcast <2 x i3> %sext2 to <1 x i6>
+  %and1 = and <1 x i6> %bc1, %a
+  %and2 = and <1 x i6> %bc2, %b
+  %or = or <1 x i6> %and1, %and2
+  ret <1 x i6> %or
+}
+
+; TODO:
+; Extra uses may prevent other transforms from creating the canonical patterns.
+
+define i8 @sext_cond_extra_uses(i1 %cmp, i8 %a, i8 %b) {
+; CHECK-LABEL: @sext_cond_extra_uses(
+; CHECK-NEXT:    [[NEG:%.*]] = xor i1 [[CMP:%.*]], true
+; CHECK-NEXT:    [[SEXT1:%.*]] = sext i1 [[CMP]] to i8
+; CHECK-NEXT:    call void @use(i8 [[SEXT1]])
+; CHECK-NEXT:    [[SEXT2:%.*]] = sext i1 [[NEG]] to i8
+; CHECK-NEXT:    call void @use(i8 [[SEXT2]])
+; CHECK-NEXT:    [[AND1:%.*]] = and i8 [[SEXT1]], [[A:%.*]]
+; CHECK-NEXT:    [[AND2:%.*]] = and i8 [[SEXT2]], [[B:%.*]]
+; CHECK-NEXT:    [[OR:%.*]] = or i8 [[AND1]], [[AND2]]
+; CHECK-NEXT:    ret i8 [[OR]]
+;
+  %neg = xor i1 %cmp, -1
+  %sext1 = sext i1 %cmp to i8
+  call void @use(i8 %sext1)
+  %sext2 = sext i1 %neg to i8
+  call void @use(i8 %sext2)
+  %and1 = and i8 %sext1, %a
+  %and2 = and i8 %sext2, %b
+  %or = or i8 %and1, %and2
+  ret i8 %or
+}
-- 
2.7.4