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[InstSimplify] Fix missed optimization in simplifyUnsignedRangeCheck() 

For both operands are unsigned, the following optimizations are valid, and missing:

   1. X > Y && X != 0 --> X > Y
   2. X > Y || X != 0 --> X != 0
   3. X <= Y || X != 0 --> true
   4. X <= Y || X == 0 --> X <= Y
   5. X > Y && X == 0 --> false

unsigned foo(unsigned x, unsigned y) { return x > y && x != 0; }
should fold to x > y, but I found we haven't done it right now.
besides, unsigned foo(unsigned x, unsigned y) { return x < y && y != 0; }
Has been folded to x < y, so there may be a bug.

Patch by: Li Jia He!

Differential Revision: https://reviews.llvm.org/D47922

llvm-svn: 335129
This commit is contained in:
Sanjay Patel 2018-06-20 14:22:49 +00:00
parent c1d2177f9d
commit 0c57de4c21
2 changed files with 7 additions and 19 deletions
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2
llvm/lib/Analysis/InstructionSimplify.cpp
View File

@ -1313,7 +1313,7 @@ static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
ICmpInst::isUnsigned(UnsignedPred))
;
else if (match(UnsignedICmp,
m_ICmp(UnsignedPred, m_Value(Y), m_Specific(X))) &&
m_ICmp(UnsignedPred, m_Specific(Y), m_Value(X))) &&
ICmpInst::isUnsigned(UnsignedPred))
UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred);
else

24
llvm/test/Transforms/InstSimplify/AndOrXor.ll
View File

@ -375,9 +375,7 @@ define i1 @and_icmp1(i32 %x, i32 %y) {
define i1 @and_icmp2(i32 %x, i32 %y) {
; CHECK-LABEL: @and_icmp2(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[X]], 0
; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: ret i1 [[TMP3]]
; CHECK-NEXT: ret i1 [[TMP1]]
;
%1 = icmp ugt i32 %x, %y
%2 = icmp ne i32 %x, 0
@ -397,10 +395,7 @@ define i1 @and_icmp3(i32 %x, i32 %y) {
define i1 @and_icmp4(i32 %x, i32 %y) {
; CHECK-LABEL: @and_icmp4(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[X]], 0
; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: ret i1 [[TMP3]]
; CHECK-NEXT: ret i1 false
;
%1 = icmp ugt i32 %x, %y
%2 = icmp eq i32 %x, 0
@ -421,10 +416,8 @@ define i1 @or_icmp1(i32 %x, i32 %y) {
define i1 @or_icmp2(i32 %x, i32 %y) {
; CHECK-LABEL: @or_icmp2(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[X]], 0
; CHECK-NEXT: [[TMP3:%.*]] = or i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: ret i1 [[TMP3]]
; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i32 [[X:%.*]], 0
; CHECK-NEXT: ret i1 [[TMP1]]
;
%1 = icmp ugt i32 %x, %y
%2 = icmp ne i32 %x, 0
@ -444,10 +437,7 @@ define i1 @or_icmp3(i32 %x, i32 %y) {
define i1 @or_icmp4(i32 %x, i32 %y) {
; CHECK-LABEL: @or_icmp4(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ule i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[X]], 0
; CHECK-NEXT: [[TMP3:%.*]] = or i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: ret i1 [[TMP3]]
; CHECK-NEXT: ret i1 true
;
%1 = icmp ule i32 %x, %y
%2 = icmp ne i32 %x, 0
@ -469,9 +459,7 @@ define i1 @or_icmp5(i32 %x, i32 %y) {
define i1 @or_icmp6(i32 %x, i32 %y) {
; CHECK-LABEL: @or_icmp6(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ule i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[X]], 0
; CHECK-NEXT: [[TMP3:%.*]] = or i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: ret i1 [[TMP3]]
; CHECK-NEXT: ret i1 [[TMP1]]
;
%1 = icmp ule i32 %x, %y
%2 = icmp eq i32 %x, 0