diff options
| -rw-r--r-- | llvm/lib/Target/X86/README-MMX.txt | 29 |
1 files changed, 0 insertions, 29 deletions
diff --git a/llvm/lib/Target/X86/README-MMX.txt b/llvm/lib/Target/X86/README-MMX.txt index a6c8616b6d2..f3a625e65dc 100644 --- a/llvm/lib/Target/X86/README-MMX.txt +++ b/llvm/lib/Target/X86/README-MMX.txt @@ -40,32 +40,3 @@ _qux: movl %edx, 4(%eax) addl $12, %esp ret $4 - -//===---------------------------------------------------------------------===// - -We generate crappy code for this: - -__m64 t() { - return _mm_cvtsi32_si64(1); -} - -_t: - subl $12, %esp - movl $1, %eax - movd %eax, %mm0 - movq %mm0, (%esp) - movl (%esp), %eax - movl 4(%esp), %edx - addl $12, %esp - ret - -The extra stack traffic is covered in the previous entry. But the other reason -is we are not smart about materializing constants in MMX registers. With -m64 - - movl $1, %eax - movd %eax, %mm0 - movd %mm0, %rax - ret - -We should be using a constantpool load instead: - movq LC0(%rip), %rax |
