diff options
| -rw-r--r-- | lib/Target/X86/README.txt | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index 3bbf3c26e4..50d87bc173 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -426,3 +426,20 @@ When: "movl $_dst, _ptr" is sufficient. //===---------------------------------------------------------------------===// Use fisttp to do FP to integer conversion whenever it is available. + +//===---------------------------------------------------------------------===// + +Instead of the following for memset char*, 1, 10: + + movl $16843009, 4(%edx) + movl $16843009, (%edx) + movw $257, 8(%edx) + +It might be better to generate + + movl $16843009, %eax + movl %eax, 4(%edx) + movl %eax, (%edx) + movw al, 8(%edx) + +when we can spare a register. It reduces code size. |