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| author | Chris Lattner <sabre@nondot.org> | 2006-09-25 17:12:14 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2006-09-25 17:12:14 +0000 |
| commit | fb981f3feec6decbe24452680b88c0203f9e5fbb (patch) | |
| tree | 32833bd5db9c9f91668355c207736827b642538a /lib | |
| parent | 279f053eae35729f449f38e08618664b118806bd (diff) | |
| download | external_llvm-fb981f3feec6decbe24452680b88c0203f9e5fbb.zip external_llvm-fb981f3feec6decbe24452680b88c0203f9e5fbb.tar.gz external_llvm-fb981f3feec6decbe24452680b88c0203f9e5fbb.tar.bz2 | |
more notes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30598 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/README.txt | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt index aa34ac7..48298fa 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -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]; +} + +//===---------------------------------------------------------------------===// |