diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index dda35f65c2a..d5f3e9c53e2 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -3748,26 +3748,6 @@ SDValue DAGCombiner::visitSHL(SDNode *N) { } } - // fold (shl (zext (srl x, C)), C) -> (zext (shl (srl x, C), C)) - // Only fold this if the inner zext has no other uses to avoid increasing - // the total number of instructions. - if (N1C && N0.getOpcode() == ISD::ZERO_EXTEND && N0.hasOneUse() && - N0.getOperand(0).getOpcode() == ISD::SRL && - isa(N0.getOperand(0)->getOperand(1))) { - uint64_t c1 = - cast(N0.getOperand(0)->getOperand(1))->getZExtValue(); - if (c1 < VT.getSizeInBits()) { - uint64_t c2 = N1C->getZExtValue(); - if (c1 == c2) { - SDValue NewOp0 = N0.getOperand(0); - EVT ShiftVT = NewOp0.getValueType(); - SDValue NewSHL = DAG.getNode(ISD::SHL, SDLoc(N), ShiftVT, - NewOp0, DAG.getConstant(c2, ShiftVT)); - return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N0), VT, NewSHL); - } - } - } - // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or // (and (srl x, (sub c1, c2), MASK) // Only fold this if the inner shift has no other uses -- if it does, folding diff --git a/test/CodeGen/X86/dagcombine-shifts.ll b/test/CodeGen/X86/dagcombine-shifts.ll deleted file mode 100644 index 0126edc2756..00000000000 --- a/test/CodeGen/X86/dagcombine-shifts.ll +++ /dev/null @@ -1,181 +0,0 @@ -; RUN: llc < %s -mtriple=x86_64-linux-gnu | FileCheck %s - -; fold (shl (zext (lshr (A, X))), X) -> (zext (shl (lshr (A, X)), X)) - -; Canolicalize the sequence shl/zext/lshr performing the zeroextend -; as the last instruction of the sequence. -; This will help DAGCombiner to identify and then fold the sequence -; of shifts into a single AND. -; This transformation is profitable if the shift amounts are the same -; and if there is only one use of the zext. - -define i16 @fun1(i8 zeroext %v) { -entry: - %shr = lshr i8 %v, 4 - %ext = zext i8 %shr to i16 - %shl = shl i16 %ext, 4 - ret i16 %shl -} - -; CHECK-LABEL: @fun1 -; CHECK: and -; CHECK-NOT: shr -; CHECK-NOT: shl -; CHECK: ret - -define i32 @fun2(i8 zeroext %v) { -entry: - %shr = lshr i8 %v, 4 - %ext = zext i8 %shr to i32 - %shl = shl i32 %ext, 4 - ret i32 %shl -} - -; CHECK-LABEL: @fun2 -; CHECK: and -; CHECK-NOT: shr -; CHECK-NOT: shl -; CHECK: ret - -define i32 @fun3(i16 zeroext %v) { -entry: - %shr = lshr i16 %v, 4 - %ext = zext i16 %shr to i32 - %shl = shl i32 %ext, 4 - ret i32 %shl -} - -; CHECK-LABEL: @fun3 -; CHECK: and -; CHECK-NOT: shr -; CHECK-NOT: shl -; CHECK: ret - -define i64 @fun4(i8 zeroext %v) { -entry: - %shr = lshr i8 %v, 4 - %ext = zext i8 %shr to i64 - %shl = shl i64 %ext, 4 - ret i64 %shl -} - -; CHECK-LABEL: @fun4 -; CHECK: and -; CHECK-NOT: shr -; CHECK-NOT: shl -; CHECK: ret - -define i64 @fun5(i16 zeroext %v) { -entry: - %shr = lshr i16 %v, 4 - %ext = zext i16 %shr to i64 - %shl = shl i64 %ext, 4 - ret i64 %shl -} - -; CHECK-LABEL: @fun5 -; CHECK: and -; CHECK-NOT: shr -; CHECK-NOT: shl -; CHECK: ret - -define i64 @fun6(i32 zeroext %v) { -entry: - %shr = lshr i32 %v, 4 - %ext = zext i32 %shr to i64 - %shl = shl i64 %ext, 4 - ret i64 %shl -} - -; CHECK-LABEL: @fun6 -; CHECK: and -; CHECK-NOT: shr -; CHECK-NOT: shl -; CHECK: ret - -; Don't fold the pattern if we use arithmetic shifts. - -define i64 @fun7(i8 zeroext %v) { -entry: - %shr = ashr i8 %v, 4 - %ext = zext i8 %shr to i64 - %shl = shl i64 %ext, 4 - ret i64 %shl -} - -; CHECK-LABEL: @fun7 -; CHECK: sar -; CHECK: shl -; CHECK: ret - -define i64 @fun8(i16 zeroext %v) { -entry: - %shr = ashr i16 %v, 4 - %ext = zext i16 %shr to i64 - %shl = shl i64 %ext, 4 - ret i64 %shl -} - -; CHECK-LABEL: @fun8 -; CHECK: sar -; CHECK: shl -; CHECK: ret - -define i64 @fun9(i32 zeroext %v) { -entry: - %shr = ashr i32 %v, 4 - %ext = zext i32 %shr to i64 - %shl = shl i64 %ext, 4 - ret i64 %shl -} - -; CHECK-LABEL: @fun9 -; CHECK: sar -; CHECK: shl -; CHECK: ret - -; Don't fold the pattern if there is more than one use of the -; operand in input to the shift left. - -define i64 @fun10(i8 zeroext %v) { -entry: - %shr = lshr i8 %v, 4 - %ext = zext i8 %shr to i64 - %shl = shl i64 %ext, 4 - %add = add i64 %shl, %ext - ret i64 %add -} - -; CHECK-LABEL: @fun10 -; CHECK: shr -; CHECK: shl -; CHECK: ret - -define i64 @fun11(i16 zeroext %v) { -entry: - %shr = lshr i16 %v, 4 - %ext = zext i16 %shr to i64 - %shl = shl i64 %ext, 4 - %add = add i64 %shl, %ext - ret i64 %add -} - -; CHECK-LABEL: @fun11 -; CHECK: shr -; CHECK: shl -; CHECK: ret - -define i64 @fun12(i32 zeroext %v) { -entry: - %shr = lshr i32 %v, 4 - %ext = zext i32 %shr to i64 - %shl = shl i64 %ext, 4 - %add = add i64 %shl, %ext - ret i64 %add -} - -; CHECK-LABEL: @fun12 -; CHECK: shr -; CHECK: shl -; CHECK: ret -