diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -1783,6 +1783,10 @@ return BinaryOperator::CreateLShr(Op1, ConstantExpr::getSub(WidthC, ShAmtC)); + if (Instruction *BitOp = + matchBSwapOrBitReverse(*II, /*MatchBSwaps*/ true, + /*MatchBitReversals*/ true)) + return BitOp; // fshl i16 X, X, 8 --> bswap i16 X (reduce to more-specific form) if (Op0 == Op1 && BitWidth == 16 && match(ShAmtC, m_SpecificInt(8))) { Module *Mod = II->getModule(); diff --git a/llvm/test/Transforms/InstCombine/bswap.ll b/llvm/test/Transforms/InstCombine/bswap.ll --- a/llvm/test/Transforms/InstCombine/bswap.ll +++ b/llvm/test/Transforms/InstCombine/bswap.ll @@ -932,17 +932,7 @@ define i64 @PR60690_call_fshl(i64 %result) { ; CHECK-LABEL: @PR60690_call_fshl( -; CHECK-NEXT: [[AND_I:%.*]] = lshr i64 [[RESULT:%.*]], 8 -; CHECK-NEXT: [[SHR_I:%.*]] = and i64 [[AND_I]], 71777214294589695 -; CHECK-NEXT: [[AND1_I:%.*]] = shl i64 [[RESULT]], 8 -; CHECK-NEXT: [[SHL_I:%.*]] = and i64 [[AND1_I]], -71777214294589696 -; CHECK-NEXT: [[OR_I:%.*]] = or i64 [[SHR_I]], [[SHL_I]] -; CHECK-NEXT: [[AND_I7:%.*]] = shl i64 [[OR_I]], 16 -; CHECK-NEXT: [[SHL_I8:%.*]] = and i64 [[AND_I7]], -281470681808896 -; CHECK-NEXT: [[AND1_I9:%.*]] = lshr i64 [[OR_I]], 16 -; CHECK-NEXT: [[SHR_I10:%.*]] = and i64 [[AND1_I9]], 281470681808895 -; CHECK-NEXT: [[OR_I11:%.*]] = or i64 [[SHL_I8]], [[SHR_I10]] -; CHECK-NEXT: [[OR_I12:%.*]] = tail call i64 @llvm.fshl.i64(i64 [[OR_I11]], i64 [[OR_I11]], i64 32) +; CHECK-NEXT: [[OR_I12:%.*]] = call i64 @llvm.bswap.i64(i64 [[RESULT:%.*]]) ; CHECK-NEXT: ret i64 [[OR_I12]] ; %and.i = lshr i64 %result, 8 @@ -962,17 +952,7 @@ define i64 @PR60690_call_fshr(i64 %result) { ; CHECK-LABEL: @PR60690_call_fshr( -; CHECK-NEXT: [[AND_I:%.*]] = lshr i64 [[RESULT:%.*]], 8 -; CHECK-NEXT: [[SHR_I:%.*]] = and i64 [[AND_I]], 71777214294589695 -; CHECK-NEXT: [[AND1_I:%.*]] = shl i64 [[RESULT]], 8 -; CHECK-NEXT: [[SHL_I:%.*]] = and i64 [[AND1_I]], -71777214294589696 -; CHECK-NEXT: [[OR_I:%.*]] = or i64 [[SHR_I]], [[SHL_I]] -; CHECK-NEXT: [[AND_I7:%.*]] = shl i64 [[OR_I]], 16 -; CHECK-NEXT: [[SHL_I8:%.*]] = and i64 [[AND_I7]], -281470681808896 -; CHECK-NEXT: [[AND1_I9:%.*]] = lshr i64 [[OR_I]], 16 -; CHECK-NEXT: [[SHR_I10:%.*]] = and i64 [[AND1_I9]], 281470681808895 -; CHECK-NEXT: [[OR_I11:%.*]] = or i64 [[SHL_I8]], [[SHR_I10]] -; CHECK-NEXT: [[OR_I12:%.*]] = call i64 @llvm.fshl.i64(i64 [[OR_I11]], i64 [[OR_I11]], i64 32) +; CHECK-NEXT: [[OR_I12:%.*]] = call i64 @llvm.bswap.i64(i64 [[RESULT:%.*]]) ; CHECK-NEXT: ret i64 [[OR_I12]] ; %and.i = lshr i64 %result, 8