From: Roman Lebedev <lebedev.ri@gmail.com>
Date: Wed, 25 Sep 2019 22:59:41 +0000 (+0000)
Subject: [InstSimplify] Handle more 'A </>/>=/<= B &&/|| (A - B) !=/== 0' patterns (PR43251)
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=04d4f957bc349c0f5991014f3f85ce39ebf97cb9;p=llvm

[InstSimplify] Handle more 'A </>/>=/<= B &&/|| (A - B) !=/== 0' patterns (PR43251)

https://rise4fun.com/Alive/sl9s
https://rise4fun.com/Alive/2plN

https://bugs.llvm.org/show_bug.cgi?id=43251

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@372928 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index dd477fe1c5d..2a911a91e29 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -1401,6 +1401,18 @@ static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
            UnsignedPred == ICmpInst::ICMP_UGT) &&
           EqPred == ICmpInst::ICMP_EQ && IsAnd)
         return ConstantInt::getFalse(UnsignedICmp->getType());
+
+      // A </> B && (A - B) != 0  <-->  A </> B
+      // A </> B || (A - B) != 0  <-->  (A - B) != 0
+      if (EqPred == ICmpInst::ICMP_NE && (UnsignedPred == ICmpInst::ICMP_ULT ||
+                                          UnsignedPred == ICmpInst::ICMP_UGT))
+        return IsAnd ? UnsignedICmp : ZeroICmp;
+
+      // A <=/>= B && (A - B) == 0  <-->  (A - B) == 0
+      // A <=/>= B || (A - B) == 0  <-->  A <=/>= B
+      if (EqPred == ICmpInst::ICMP_EQ && (UnsignedPred == ICmpInst::ICMP_ULE ||
+                                          UnsignedPred == ICmpInst::ICMP_UGE))
+        return IsAnd ? ZeroICmp : UnsignedICmp;
     }
 
     // Given  Y = (A - B)
diff --git a/test/Transforms/InstCombine/result-of-usub-is-non-zero-and-no-overflow.ll b/test/Transforms/InstCombine/result-of-usub-is-non-zero-and-no-overflow.ll
index 26bbc445296..987bf7345bb 100644
--- a/test/Transforms/InstCombine/result-of-usub-is-non-zero-and-no-overflow.ll
+++ b/test/Transforms/InstCombine/result-of-usub-is-non-zero-and-no-overflow.ll
@@ -65,8 +65,7 @@ define i1 @t1_strict(i8 %base, i8 %offset) {
 ; CHECK-NEXT:    call void @use1(i1 [[NO_UNDERFLOW]])
 ; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
 ; CHECK-NEXT:    call void @use1(i1 [[NOT_NULL]])
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    ret i1 [[TMP1]]
+; CHECK-NEXT:    ret i1 [[NO_UNDERFLOW]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
@@ -226,8 +225,7 @@ define i1 @t7_nonstrict(i8 %base, i8 %offset) {
 ; CHECK-NEXT:    call void @use1(i1 [[UNDERFLOW]])
 ; CHECK-NEXT:    [[NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0
 ; CHECK-NEXT:    call void @use1(i1 [[NULL]])
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ule i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    ret i1 [[TMP1]]
+; CHECK-NEXT:    ret i1 [[UNDERFLOW]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
diff --git a/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll b/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll
index f0a9d27f3d6..fd473ac9d25 100644
--- a/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll
+++ b/test/Transforms/InstSimplify/result-of-usub-is-non-zero-and-no-overflow.ll
@@ -98,10 +98,8 @@ define i1 @exaustive_t0_no_underflow(i8 %base, i8 %offset) {
 ; CHECK-LABEL: @exaustive_t0_no_underflow(
 ; CHECK-NEXT:    [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
-; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
 ; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 [[NO_UNDERFLOW]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
@@ -116,9 +114,7 @@ define i1 @exaustive_t1_not_null(i8 %base, i8 %offset) {
 ; CHECK-NEXT:    [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
 ; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
-; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    [[R:%.*]] = or i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 [[NOT_NULL]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
@@ -163,10 +159,8 @@ define i1 @exaustive_t4_no_underflow(i8 %base, i8 %offset) {
 ; CHECK-LABEL: @exaustive_t4_no_underflow(
 ; CHECK-NEXT:    [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
-; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
 ; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 [[NO_UNDERFLOW]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
@@ -181,9 +175,7 @@ define i1 @exaustive_t5_not_null(i8 %base, i8 %offset) {
 ; CHECK-NEXT:    [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
 ; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
-; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ugt i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    [[R:%.*]] = or i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 [[NOT_NULL]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
@@ -260,9 +252,7 @@ define i1 @exaustive_t10_not_null(i8 %base, i8 %offset) {
 ; CHECK-NEXT:    [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
 ; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0
-; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 [[NOT_NULL]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
@@ -276,10 +266,8 @@ define i1 @exaustive_t11_no_underflow(i8 %base, i8 %offset) {
 ; CHECK-LABEL: @exaustive_t11_no_underflow(
 ; CHECK-NEXT:    [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
-; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0
 ; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    [[R:%.*]] = or i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 [[NO_UNDERFLOW]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
@@ -325,9 +313,7 @@ define i1 @exaustive_t14_not_null(i8 %base, i8 %offset) {
 ; CHECK-NEXT:    [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
 ; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0
-; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp uge i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 [[NOT_NULL]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)
@@ -341,10 +327,8 @@ define i1 @exaustive_t15_no_underflow(i8 %base, i8 %offset) {
 ; CHECK-LABEL: @exaustive_t15_no_underflow(
 ; CHECK-NEXT:    [[ADJUSTED:%.*]] = sub i8 [[BASE:%.*]], [[OFFSET:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
-; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp eq i8 [[ADJUSTED]], 0
 ; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp uge i8 [[BASE]], [[OFFSET]]
-; CHECK-NEXT:    [[R:%.*]] = or i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 [[NO_UNDERFLOW]]
 ;
   %adjusted = sub i8 %base, %offset
   call void @use8(i8 %adjusted)