[llvm] f1dfa49 - [ValueTracking] Add logic for `isKnownNonZero(sshl.sat/ushl.sat X, Y)`
Noah Goldstein via llvm-commits
llvm-commits at lists.llvm.org
Sun Apr 30 08:07:15 PDT 2023
Author: Noah Goldstein
Date: 2023-04-30T10:06:45-05:00
New Revision: f1dfa4938a2f608b6288cf55da905a440b2763d6
URL: https://github.com/llvm/llvm-project/commit/f1dfa4938a2f608b6288cf55da905a440b2763d6
DIFF: https://github.com/llvm/llvm-project/commit/f1dfa4938a2f608b6288cf55da905a440b2763d6.diff
LOG: [ValueTracking] Add logic for `isKnownNonZero(sshl.sat/ushl.sat X, Y)`
`(sshl/ushl X, Y) != 0` -> `X != 0`
Alive2 Links
https://alive2.llvm.org/ce/z/4WLM2p
https://alive2.llvm.org/ce/z/BHFng4
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D149411
Added:
Modified:
llvm/lib/Analysis/ValueTracking.cpp
llvm/test/Analysis/ValueTracking/known-non-zero.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index da369c91c0c0..0439f4e5f0d2 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -2920,6 +2920,8 @@ bool isKnownNonZero(const Value *V, const APInt &DemandedElts, unsigned Depth,
case Instruction::Call:
if (auto *II = dyn_cast<IntrinsicInst>(I)) {
switch (II->getIntrinsicID()) {
+ case Intrinsic::sshl_sat:
+ case Intrinsic::ushl_sat:
case Intrinsic::abs:
case Intrinsic::bitreverse:
case Intrinsic::bswap:
diff --git a/llvm/test/Analysis/ValueTracking/known-non-zero.ll b/llvm/test/Analysis/ValueTracking/known-non-zero.ll
index 52f809cd13cf..61cbe13db027 100644
--- a/llvm/test/Analysis/ValueTracking/known-non-zero.ll
+++ b/llvm/test/Analysis/ValueTracking/known-non-zero.ll
@@ -803,10 +803,7 @@ define i1 @sshl_nonzero(i8 %xx, i8 %y, i8 %ind) {
; CHECK-LABEL: @sshl_nonzero(
; CHECK-NEXT: [[X_NZ:%.*]] = icmp ne i8 [[XX:%.*]], 0
; CHECK-NEXT: call void @llvm.assume(i1 [[X_NZ]])
-; CHECK-NEXT: [[X:%.*]] = call i8 @llvm.sshl.sat.i8(i8 [[XX]], i8 [[Y:%.*]])
-; CHECK-NEXT: [[Z:%.*]] = or i8 [[X]], [[IND:%.*]]
-; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[Z]], 0
-; CHECK-NEXT: ret i1 [[R]]
+; CHECK-NEXT: ret i1 false
;
%x_nz = icmp ne i8 %xx, 0
call void @llvm.assume(i1 %x_nz)
@@ -833,10 +830,7 @@ define i1 @ushl_nonzero(i8 %xx, i8 %y, i8 %ind) {
; CHECK-LABEL: @ushl_nonzero(
; CHECK-NEXT: [[X_NZ:%.*]] = icmp ne i8 [[XX:%.*]], 0
; CHECK-NEXT: call void @llvm.assume(i1 [[X_NZ]])
-; CHECK-NEXT: [[X:%.*]] = call i8 @llvm.ushl.sat.i8(i8 [[XX]], i8 [[Y:%.*]])
-; CHECK-NEXT: [[Z:%.*]] = or i8 [[X]], [[IND:%.*]]
-; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[Z]], 0
-; CHECK-NEXT: ret i1 [[R]]
+; CHECK-NEXT: ret i1 false
;
%x_nz = icmp ne i8 %xx, 0
call void @llvm.assume(i1 %x_nz)
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