From f1dfa4938a2f608b6288cf55da905a440b2763d6 Mon Sep 17 00:00:00 2001 From: Noah Goldstein Date: Sun, 30 Apr 2023 09:33:00 -0500 Subject: [PATCH] [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 --- llvm/lib/Analysis/ValueTracking.cpp | 2 ++ llvm/test/Analysis/ValueTracking/known-non-zero.ll | 10 ++-------- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index da369c91..0439f4e 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(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 52f809cd..61cbe13d 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) -- 2.7.4