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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30598 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-09-25 17:12:14 +00:00
parent 279f053eae
commit fb981f3fee
1 changed files with 22 additions and 0 deletions
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22
lib/Target/README.txt
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@ -264,3 +264,25 @@ It would also be nice to recognize the reg->size doesn't alias reg->node[i], but
alas...
//===---------------------------------------------------------------------===//
This isn't recognized as bswap by instcombine:
unsigned int swap_32(unsigned int v) {
v = ((v & 0x00ff00ffU) << 8) | ((v & 0xff00ff00U) >> 8);
v = ((v & 0x0000ffffU) << 16) | ((v & 0xffff0000U) >> 16);
return v;
}
//===---------------------------------------------------------------------===//
These should turn into single 16-bit (unaligned?) loads on little/big endian
processors.
unsigned short read_16_le(const unsigned char *adr) {
return adr[0] | (adr[1] << 8);
}
unsigned short read_16_be(const unsigned char *adr) {
return (adr[0] << 8) | adr[1];
}
//===---------------------------------------------------------------------===//