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* [Bug target/22076] New: Strange code for MMX register moves
@ 2005-06-15 12:40 uros at kss-loka dot si
2005-06-15 12:57 ` [Bug target/22076] " falk at debian dot org
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: uros at kss-loka dot si @ 2005-06-15 12:40 UTC (permalink / raw)
To: gcc-bugs
This testcase:
#include <mmintrin.h>
__m64 test() {
__m64 a;
return a;
}
results in quite strange code when compiled with '-O2 -mmmx':
test:
pushl %ebp
movl %esp, %ebp
subl $8, %esp
movl %eax, -8(%ebp) <<<<
movl %edx, -4(%ebp) <<<<
movq -8(%ebp), %mm0
leave
ret
If xmm registers are used (change __m64 into __m128), asm code is OK.
It looks there are some problems with register costs, from _.22.lreg:
Pass 0
Register 58 costs: AD_REGS:13000 Q_REGS:13000 NON_Q_REGS:13000
INDEX_REGS:13000 LEGACY_REGS:13000 GENERAL_REGS:13000 MMX_REGS:24000
FLOAT_INT_REGS:30000 INT_SSE_REGS:30000 FLOAT_INT_SSE_REGS:30000 ALL_REGS:30000
MEM:20000
Register 58 pref GENERAL_REGS or none
Pass 1
Register 58 costs: AD_REGS:13000 Q_REGS:13000 NON_Q_REGS:13000
INDEX_REGS:13000 LEGACY_REGS:13000 GENERAL_REGS:13000 MMX_REGS:24000
FLOAT_INT_REGS:30000 INT_SSE_REGS:30000 FLOAT_INT_SSE_REGS:30000 ALL_REGS:30000
MEM:20000
...
(insn:HI 16 28 22 1 (set (reg/i:V2SI 29 mm0 [ <result> ])
(reg/v:V2SI 58 [ a ])) 768 {*movv2si_internal} (nil)
(expr_list:REG_DEAD (reg/v:V2SI 58 [ a ])
(nil)))
...
The instructions, marked with '<<<<' are then produced by reload.
--
Summary: Strange code for MMX register moves
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Keywords: ssemmx
Severity: normal
Priority: P2
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: uros at kss-loka dot si
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076
^ permalink raw reply [flat|nested] 9+ messages in thread* [Bug target/22076] Strange code for MMX register moves 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si @ 2005-06-15 12:57 ` falk at debian dot org 2005-06-15 17:35 ` pinskia at gcc dot gnu dot org ` (6 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: falk at debian dot org @ 2005-06-15 12:57 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From falk at debian dot org 2005-06-15 12:56 ------- (In reply to comment #0) > This testcase: > #include <mmintrin.h> > > __m64 test() { > __m64 a; > > return a; > } Well, this is invalid code, so it's not really important what the code looks like. If it also occurs in valid code, it might be related to PR 7061. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug target/22076] Strange code for MMX register moves 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si 2005-06-15 12:57 ` [Bug target/22076] " falk at debian dot org @ 2005-06-15 17:35 ` pinskia at gcc dot gnu dot org 2005-06-21 12:04 ` uros at kss-loka dot si ` (5 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-06-15 17:35 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-15 17:35 ------- a is uninitialized so what do you expect? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug target/22076] Strange code for MMX register moves 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si 2005-06-15 12:57 ` [Bug target/22076] " falk at debian dot org 2005-06-15 17:35 ` pinskia at gcc dot gnu dot org @ 2005-06-21 12:04 ` uros at kss-loka dot si 2005-06-21 13:06 ` pinskia at gcc dot gnu dot org ` (4 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: uros at kss-loka dot si @ 2005-06-21 12:04 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From uros at kss-loka dot si 2005-06-21 12:04 ------- New testcase (everything is initialized this time): --cut here-- #include <mmintrin.h> __v8qi test () { __v8qi mm0 = {1,2,3,4,5,6,7,8}; __v8qi mm1 = {11,22,33,44,55,66,77,88}; volatile __m64 x; x = _mm_add_pi8 (mm0, mm1); return x; } --cut here-- Pass 0 Register 67 costs: AD_REGS:4000 Q_REGS:4000 NON_Q_REGS:4000 INDEX_REGS:4000 LEGACY_REGS:4000 GENERAL_REGS:4000 MMX_REGS:46000 INT_SSE_REGS:38000 MEM:16000 Register 67 pref GENERAL_REGS or none Pass 1 Register 67 costs: AD_REGS:4000 Q_REGS:4000 NON_Q_REGS:4000 INDEX_REGS:4000 LEGACY_REGS:4000 GENERAL_REGS:4000 MMX_REGS:46000 INT_SSE_REGS:38000 MEM:16000 69 registers. ... (insn:HI 18 45 22 1 (set (reg:V8QI 67) (mem/u/i:V8QI (symbol_ref/u:SI ("*.LC2") [flags 0x2]) [0 S8 A64])) 766 {*movv8qi_internal} (nil) (expr_list:REG_EQUIV (const_vector:V8QI [ (const_int 12 [0xc]) (const_int 24 [0x18]) (const_int 36 [0x24]) (const_int 48 [0x30]) (const_int 60 [0x3c]) (const_int 72 [0x48]) (const_int 84 [0x54]) (const_int 96 [0x60]) ]) (nil))) ... test: pushl %ebp movl %esp, %ebp subl $24, %esp movl $807671820, %eax movl $1616136252, %edx movl %eax, -8(%ebp) movl %edx, -4(%ebp) movl -8(%ebp), %eax movl -4(%ebp), %edx movl %eax, -24(%ebp) movl %edx, -20(%ebp) movq -24(%ebp), %mm1 leave movq %mm1, %mm0 ret -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug target/22076] Strange code for MMX register moves 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si ` (2 preceding siblings ...) 2005-06-21 12:04 ` uros at kss-loka dot si @ 2005-06-21 13:06 ` pinskia at gcc dot gnu dot org 2005-06-22 20:27 ` pinskia at gcc dot gnu dot org ` (3 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-06-21 13:06 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-21 13:06 ------- I think this is more related to PR 14552 which was shown by me that we regressed because we did not output emms at all before so not emmiting mmx instructions without use of the functions in mmintrin.h -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug target/22076] Strange code for MMX register moves 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si ` (3 preceding siblings ...) 2005-06-21 13:06 ` pinskia at gcc dot gnu dot org @ 2005-06-22 20:27 ` pinskia at gcc dot gnu dot org 2005-06-22 20:29 ` pinskia at gcc dot gnu dot org ` (2 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-06-22 20:27 UTC (permalink / raw) To: gcc-bugs -- What |Removed |Added ---------------------------------------------------------------------------- OtherBugsDependingO| |22152 nThis| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug target/22076] Strange code for MMX register moves 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si ` (4 preceding siblings ...) 2005-06-22 20:27 ` pinskia at gcc dot gnu dot org @ 2005-06-22 20:29 ` pinskia at gcc dot gnu dot org 2005-08-31 19:18 ` pinskia at gcc dot gnu dot org 2005-08-31 20:42 ` bangerth at dealii dot org 7 siblings, 0 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-06-22 20:29 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-22 20:27 ------- Confirmed. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Keywords| |missed-optimization Last reconfirmed|0000-00-00 00:00:00 |2005-06-22 20:27:37 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug target/22076] Strange code for MMX register moves 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si ` (5 preceding siblings ...) 2005-06-22 20:29 ` pinskia at gcc dot gnu dot org @ 2005-08-31 19:18 ` pinskia at gcc dot gnu dot org 2005-08-31 20:42 ` bangerth at dealii dot org 7 siblings, 0 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-08-31 19:18 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-08-31 19:18 ------- *** Bug 23660 has been marked as a duplicate of this bug. *** -- What |Removed |Added ---------------------------------------------------------------------------- CC| |vahur dot sinijarv at | |cydonia dot ee http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug target/22076] Strange code for MMX register moves 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si ` (6 preceding siblings ...) 2005-08-31 19:18 ` pinskia at gcc dot gnu dot org @ 2005-08-31 20:42 ` bangerth at dealii dot org 7 siblings, 0 replies; 9+ messages in thread From: bangerth at dealii dot org @ 2005-08-31 20:42 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From bangerth at dealii dot org 2005-08-31 20:34 ------- In the discussion on the duplicate PR 23660, rth explained part of this here: http://gcc.gnu.org/ml/gcc/2005-08/msg00934.html W. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22076 ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2005-08-31 20:34 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2005-06-15 12:40 [Bug target/22076] New: Strange code for MMX register moves uros at kss-loka dot si 2005-06-15 12:57 ` [Bug target/22076] " falk at debian dot org 2005-06-15 17:35 ` pinskia at gcc dot gnu dot org 2005-06-21 12:04 ` uros at kss-loka dot si 2005-06-21 13:06 ` pinskia at gcc dot gnu dot org 2005-06-22 20:27 ` pinskia at gcc dot gnu dot org 2005-06-22 20:29 ` pinskia at gcc dot gnu dot org 2005-08-31 19:18 ` pinskia at gcc dot gnu dot org 2005-08-31 20:42 ` bangerth at dealii dot org
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