From: Sanjay Patel <spatel@rotateright.com>
Date: Thu, 13 Apr 2017 15:46:39 +0000 (+0000)
Subject: [InstCombine] add/move tests for or-of-icmps; NFC
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=718498681fb464f86d9b3adcf2157b3735ec4dda;p=llvm

[InstCombine] add/move tests for or-of-icmps; NFC

If we had these tests, the bug caused by https://reviews.llvm.org/rL299851 would have been caught sooner.
There's also an assert in the code that should have caught that bug, but the assert line itself has a bug.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300201 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/test/Transforms/InstCombine/icmp.ll b/test/Transforms/InstCombine/icmp.ll
index b1dc395b3d9..edfa9a10291 100644
--- a/test/Transforms/InstCombine/icmp.ll
+++ b/test/Transforms/InstCombine/icmp.ll
@@ -1123,19 +1123,6 @@ define i1 @test68(i32 %x) {
   ret i1 %cmp
 }
 
-; PR14708
-define i1 @test69(i32 %c) {
-; CHECK-LABEL: @test69(
-; CHECK-NEXT:    [[TMP1:%.*]] = or i32 %c, 32
-; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 97
-; CHECK-NEXT:    ret i1 [[TMP2]]
-;
-  %1 = icmp eq i32 %c, 97
-  %2 = icmp eq i32 %c, 65
-  %3 = or i1 %1, %2
-  ret i1 %3
-}
-
 ; PR15940
 define i1 @test70(i32 %X) {
 ; CHECK-LABEL: @test70(
diff --git a/test/Transforms/InstCombine/or.ll b/test/Transforms/InstCombine/or.ll
index 2ac6f5b1104..bf575418ce9 100644
--- a/test/Transforms/InstCombine/or.ll
+++ b/test/Transforms/InstCombine/or.ll
@@ -207,31 +207,79 @@ define <2 x i1> @test18vec(<2 x i32> %A) {
   ret <2 x i1> %D
 }
 
-define i1 @test19(i32 %A) {
-; CHECK-LABEL: @test19(
-; CHECK-NEXT:    [[TMP1:%.*]] = or i32 %A, 1
+; if LHSC and RHSC differ only by one bit:
+; (A == C1 || A == C2) -> (A | (C1 ^ C2)) == C2
+; PR14708: https://bugs.llvm.org/show_bug.cgi?id=14708
+
+define i1 @cmp_eq_with_one_bit_diff_constants1(i32 %x) {
+; CHECK-LABEL: @cmp_eq_with_one_bit_diff_constants1(
+; CHECK-NEXT:    [[TMP1:%.*]] = or i32 %x, 1
 ; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 51
 ; CHECK-NEXT:    ret i1 [[TMP2]]
 ;
-  %B = icmp eq i32 %A, 50
-  %C = icmp eq i32 %A, 51
-  %D = or i1 %B, %C
-  ret i1 %D
+  %cmp1 = icmp eq i32 %x, 50
+  %cmp2 = icmp eq i32 %x, 51
+  %or = or i1 %cmp1, %cmp2
+  ret i1 %or
+}
+
+; The constants are not necessarily off-by-one, just off-by-one-bit.
+
+define i1 @cmp_eq_with_one_bit_diff_constants2(i32 %x) {
+; CHECK-LABEL: @cmp_eq_with_one_bit_diff_constants2(
+; CHECK-NEXT:    [[TMP1:%.*]] = or i32 %x, 32
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 97
+; CHECK-NEXT:    ret i1 [[TMP2]]
+;
+  %cmp1 = icmp eq i32 %x, 97
+  %cmp2 = icmp eq i32 %x, 65
+  %or = or i1 %cmp1, %cmp2
+  ret i1 %or
+}
+
+; Make sure the constants are treated as unsigned when comparing them.
+
+define i1 @cmp_eq_with_one_bit_diff_constants3(i8 %x) {
+; CHECK-LABEL: @cmp_eq_with_one_bit_diff_constants3(
+; CHECK-NEXT:    [[TMP1:%.*]] = or i8 %x, -128
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], -2
+; CHECK-NEXT:    ret i1 [[TMP2]]
+;
+  %cmp1 = icmp eq i8 %x, 254
+  %cmp2 = icmp eq i8 %x, 126
+  %or = or i1 %cmp1, %cmp2
+  ret i1 %or
+}
+
+; Use an 'add' to eliminate an icmp if the constants are off-by-one (not off-by-one-bit).
+; (X == 13 | X == 14) -> X-13 <u 2
+
+define i1 @cmp_eq_with_diff_one(i8 %x) {
+; CHECK-LABEL: @cmp_eq_with_diff_one(
+; CHECK-NEXT:    [[X_OFF:%.*]] = add i8 %x, -13
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i8 [[X_OFF]], 2
+; CHECK-NEXT:    ret i1 [[TMP1]]
+;
+  %cmp1 = icmp eq i8 %x, 13
+  %cmp2 = icmp eq i8 %x, 14
+  %or = or i1 %cmp1, %cmp2
+  ret i1 %or
 }
 
+; Make sure the constants are treated as signed when comparing them.
 ; PR32524: https://bugs.llvm.org/show_bug.cgi?id=32524
 
-define i1 @or_icmps_eq_diff1(i32 %x) {
-; CHECK-LABEL: @or_icmps_eq_diff1(
+define i1 @cmp_eq_with_diff_one_signed(i32 %x) {
+; CHECK-LABEL: @cmp_eq_with_diff_one_signed(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i32 %x, -1
 ; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i32 %x, 0
-; CHECK-NEXT:    [[LOGIC:%.*]] = or i1 [[CMP1]], [[CMP2]]
-; CHECK-NEXT:    ret i1 [[LOGIC]]
+; CHECK-NEXT:    [[OR:%.*]] = or i1 [[CMP1]], [[CMP2]]
+; CHECK-NEXT:    ret i1 [[OR]]
 ;
   %cmp1 = icmp eq i32 %x, -1
   %cmp2 = icmp eq i32 %x, 0
-  %logic = or i1 %cmp1, %cmp2
-  ret i1 %logic
+  %or = or i1 %cmp1, %cmp2
+  ret i1 %or
 }
 
 define i32 @test20(i32 %x) {