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Move IsRunOfOnes to a more logical place and rename to a proper predicate form

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(lowercase isXXX).

Patch by Jim Laskey.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22708 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-08-08 21:08:09 +00:00
parent 394cd13ba3
commit 02efa6c140
1 changed files with 24 additions and 24 deletions
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48
lib/Target/PowerPC/PPCISelPattern.cpp
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@ -36,28 +36,6 @@
using namespace llvm;
// IsRunOfOnes - Returns true iff Val consists of one contiguous run of 1s with
// any number of 0s on either side. The 1s are allowed to wrap from LSB to
// MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs. 0x0F0F0000 is
// not, since all 1s are not contiguous.
static bool IsRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
if (isShiftedMask_32(Val)) {
// look for the first non-zero bit
MB = CountLeadingZeros_32(Val);
// look for the first zero bit after the run of ones
ME = CountLeadingZeros_32((Val - 1) ^ Val);
return true;
} else if (isShiftedMask_32(Val = ~Val)) { // invert mask
// effectively look for the first zero bit
ME = CountLeadingZeros_32(Val) - 1;
// effectively look for the first one bit after the run of zeros
MB = CountLeadingZeros_32((Val - 1) ^ Val) + 1;
return true;
}
// no run present
return false;
}
//===----------------------------------------------------------------------===//
// PPC32TargetLowering - PPC32 Implementation of the TargetLowering interface
namespace {
@ -602,6 +580,28 @@ public:
}
};
// isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s with
// any number of 0s on either side. The 1s are allowed to wrap from LSB to
// MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs. 0x0F0F0000 is
// not, since all 1s are not contiguous.
static bool isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
if (isShiftedMask_32(Val)) {
// look for the first non-zero bit
MB = CountLeadingZeros_32(Val);
// look for the first zero bit after the run of ones
ME = CountLeadingZeros_32((Val - 1) ^ Val);
return true;
} else if (isShiftedMask_32(Val = ~Val)) { // invert mask
// effectively look for the first zero bit
ME = CountLeadingZeros_32(Val) - 1;
// effectively look for the first one bit after the run of zeros
MB = CountLeadingZeros_32((Val - 1) ^ Val) + 1;
return true;
}
// no run present
return false;
}
/// getImmediateForOpcode - This method returns a value indicating whether
/// the ConstantSDNode N can be used as an immediate to Opcode. The return
/// values are either 0, 1 or 2. 0 indicates that either N is not a
@ -627,7 +627,7 @@ static unsigned getImmediateForOpcode(SDOperand N, unsigned Opcode,
break;
case ISD::AND: {
unsigned MB, ME;
if (IsRunOfOnes(v, MB, ME)) { Imm = MB << 16 | ME & 0xFFFF; return 5; }
if (isRunOfOnes(v, MB, ME)) { Imm = MB << 16 | ME & 0xFFFF; return 5; }
if (isUInt16(v)) { Imm = v & 0xFFFF; return 1; }
if ((v & 0x0000FFFF) == 0) { Imm = v >> 16; return 2; }
break;
@ -1036,7 +1036,7 @@ bool ISel::SelectBitfieldInsert(SDOperand OR, unsigned Result) {
// of set bits). Given that, Select the arguments and generate the rlwimi
// instruction.
unsigned MB, ME;
if (((TgtMask & InsMask) == 0) && IsRunOfOnes(InsMask, MB, ME)) {
if (((TgtMask & InsMask) == 0) && isRunOfOnes(InsMask, MB, ME)) {
unsigned Tmp1, Tmp2;
bool fullMask = (TgtMask ^ InsMask) == 0xFFFFFFFF;
// Check for rotlwi / rotrwi here, a special case of bitfield insert