6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-07-19 03:29:22 +00:00
Code Issues Projects Releases Wiki Activity

This hunk accidentally got dropped. Patch by Jim Laskey

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22595 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-08-02 19:30:55 +00:00
parent 0561b3ff9f
commit c0d590b6f2
1 changed files with 0 additions and 67 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
lib/Target/PowerPC/PPCISelPattern.cpp
View File

@ -601,73 +601,6 @@ public:
}
};
/// ExactLog2 - This function solves for (Val == 1 << (N-1)) and returns N. It
/// returns zero when the input is not exactly a power of two.
static unsigned ExactLog2(unsigned Val) {
if (Val == 0 || (Val & (Val-1))) return 0;
unsigned Count = 0;
while (Val != 1) {
Val >>= 1;
++Count;
}
return Count;
}
// IsRunOfOnes - returns true if Val consists of one contiguous run of 1's with
// any number of 0's on either side. the 1's are allowed to wrap from LSB to
// MSB. so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs. 0x0F0F0000 is
// not, since all 1's are not contiguous.
static bool IsRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
bool isRun = true;
MB = 0;
ME = 0;
// look for first set bit
int i = 0;
for (; i < 32; i++) {
if ((Val & (1 << (31 - i))) != 0) {
MB = i;
ME = i;
break;
}
}
// look for last set bit
for (; i < 32; i++) {
if ((Val & (1 << (31 - i))) == 0)
break;
ME = i;
}
// look for next set bit
for (; i < 32; i++) {
if ((Val & (1 << (31 - i))) != 0)
break;
}
// if we exhausted all the bits, we found a match at this point for 0*1*0*
if (i == 32)
return true;
// since we just encountered more 1's, if it doesn't wrap around to the
// most significant bit of the word, then we did not find a match to 1*0*1* so
// exit.
if (MB != 0)
return false;
// look for last set bit
for (MB = i; i < 32; i++) {
if ((Val & (1 << (31 - i))) == 0)
break;
}
// if we exhausted all the bits, then we found a match for 1*0*1*, otherwise,
// the value is not a run of ones.
if (i == 32)
return true;
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