------- Comment #4 from ubizjak at gmail dot com 2007-07-10 10:36 -------
(In reply to comment #0)
> long2vector() should use a simple MOVQ instruction the way int2vector() uses
> MOVD. It appears that the reason for the stack access is that the original
> code
> used a reg64->mem->mm->xmm path, which the optimizer partly noticed;
> gcc-4.3-20070617 leaves the full path in place.
>
> Also, do the vector2<X>() functions really need to access the stack?
Stack access is the remain of partially implemented TARGET_INTER_UNIT_MOVES,
and this was fully fixed in 4.3. The fact that gcc-4.3 leaves full path in
place is due to missing pattern for vec_concat:V2DI (implemented in the patch
below) where 64bit registers can be concatenated with zero (for 64bit targets)
using movq instruction.
With attached patch, 4.3 generates:
long2vector:
.LFB4:
movq %rdi, %xmm0
ret
.LFE4:
for -march=core2 (TARGET_INTER_UNIT_MOVES allowed)
and
long2vector:
.LFB4:
movq %rdi, -8(%rsp)
movq -8(%rsp), %xmm0
ret
.LFE4:
for -march=k8 (no TARGET_INTER_UNIT_MOVES allowed).
> Finally, I've noticed several places where instructions involving 64-bit
> values
> use the "d/l" suffix (e.g. "long i = 0" ==> "xorl %eax, %eax"), or 32-bit
> operations that use 64-bit registers (e.g. "movd %xmm0, %rax" above). Are
> those
> generally features, bugs, or a "who cares?"
These are "who cares", produced by reload to satisfy register constraints (i.e.
certain alternatives missing as an attempt to solve INTER_UNIT_MOVES
requirements). They are harmles.
Index: sse.md
===================================================================
--- sse.md (revision 126510)
+++ sse.md (working copy)
@@ -4717,7 +4717,7 @@
(vec_concat:V2DI
(match_operand:DI 1 "nonimmediate_operand" " m,*y ,0 ,0,0,m")
(match_operand:DI 2 "vector_move_operand" " C, C,Yt,x,m,0")))]
- "TARGET_SSE"
+ "!TARGET_64BIT && TARGET_SSE"
"@
movq\t{%1, %0|%0, %1}
movq2dq\t{%1, %0|%0, %1}
@@ -4728,6 +4728,23 @@
[(set_attr "type" "ssemov,ssemov,sselog,ssemov,ssemov,ssemov")
(set_attr "mode" "TI,TI,TI,V4SF,V2SF,V2SF")])
+(define_insn "*vec_concatv2di_rex"
+ [(set (match_operand:V2DI 0 "register_operand" "=Yt,Yi,!Yt,Yt,x,x,x")
+ (vec_concat:V2DI
+ (match_operand:DI 1 "nonimmediate_operand" " m,r ,*y ,0 ,0,0,m")
+ (match_operand:DI 2 "vector_move_operand" " C,C ,C ,Yt,x,m,0")))]
+ "TARGET_64BIT"
+ "@
+ movq\t{%1, %0|%0, %1}
+ movq\t{%1, %0|%0, %1}
+ movq2dq\t{%1, %0|%0, %1}
+ punpcklqdq\t{%2, %0|%0, %2}
+ movlhps\t{%2, %0|%0, %2}
+ movhps\t{%2, %0|%0, %2}
+ movlps\t{%1, %0|%0, %1}"
+ [(set_attr "type" "ssemov,ssemov,ssemov,sselog,ssemov,ssemov,ssemov")
+ (set_attr "mode" "TI,TI,TI,TI,V4SF,V2SF,V2SF")])
+
(define_expand "vec_setv2di"
[(match_operand:V2DI 0 "register_operand" "")
(match_operand:DI 1 "register_operand" "")
--
ubizjak at gmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |ubizjak at gmail dot com
|dot org |
Status|NEW |ASSIGNED
Last reconfirmed|2007-07-10 09:14:14 |2007-07-10 10:36:00
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32708
