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From: "uros at kss-loka dot si" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/22076] New: Strange code for MMX register moves Date: Wed, 15 Jun 2005 12:40:00 -0000 [thread overview] Message-ID: <20050615123954.22076.uros@kss-loka.si> (raw) 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
next reply other threads:[~2005-06-15 12:40 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2005-06-15 12:40 uros at kss-loka dot si [this message] 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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