mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-19 19:29:31 +00:00
An entry about comi / ucomi intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27445 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
6be2c58c8c
commit
8af5ef9c64
@ -673,3 +673,34 @@ of a v4sf value.
|
||||
Better codegen for vector_shuffles like this { x, 0, 0, 0 } or { x, 0, x, 0}.
|
||||
Perhaps use pxor / xorp* to clear a XMM register first?
|
||||
|
||||
//===---------------------------------------------------------------------===//
|
||||
|
||||
Adding to the list of cmp / test poor codegen issues:
|
||||
|
||||
int test(__m128 *A, __m128 *B) {
|
||||
if (_mm_comige_ss(*A, *B))
|
||||
return 3;
|
||||
else
|
||||
return 4;
|
||||
}
|
||||
|
||||
_test:
|
||||
movl 8(%esp), %eax
|
||||
movaps (%eax), %xmm0
|
||||
movl 4(%esp), %eax
|
||||
movaps (%eax), %xmm1
|
||||
comiss %xmm0, %xmm1
|
||||
setae %al
|
||||
movzbl %al, %ecx
|
||||
movl $3, %eax
|
||||
movl $4, %edx
|
||||
cmpl $0, %ecx
|
||||
cmove %edx, %eax
|
||||
ret
|
||||
|
||||
Note the setae, movzbl, cmpl, cmove can be replaced with a single cmovae. There
|
||||
are a number of issues. 1) We are introducing a setcc between the result of the
|
||||
intrisic call and select. 2) The intrinsic is expected to produce a i32 value
|
||||
so a any extend (which becomes a zero extend) is added.
|
||||
|
||||
We probably need some kind of target DAG combine hook to fix this.
|
||||
|
Loading…
Reference in New Issue
Block a user