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[Bug middle-end/42881] [4.5 Regression] SSE2 intrinsics miscompiled at -O0 -march=k8
- From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 27 Jan 2010 16:16:46 -0000
- Subject: [Bug middle-end/42881] [4.5 Regression] SSE2 intrinsics miscompiled at -O0 -march=k8
- References: <bug-42881-16957@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #1 from rguenth at gcc dot gnu dot org 2010-01-27 16:16 -------
At -O0 I see in .optimized:
<bb 2>:
__F_7 = 3.0e+0;
D.6259_8 = {__F_7, __F_7};
D.6258_11 = D.6259_8;
x.0_1 = D.6258_11;
x = x.0_1;
x.1_2 = x;
__P_9 = &a[0];
__A_10 = x.1_2;
__builtin_ia32_storeupd (__P_9, __A_10);
D.6247_3 = a[1];
D.6248_4 = a[0];
D.6249_5 = (const char * restrict) &"%f %f\n"[0];
printf (D.6249_5, D.6248_4, D.6247_3);
D.6250_6 = 0;
return D.6250_6;
nothing wrong here sofar. But we expand:
;; D.6259_8 = {__F_7, __F_7};
(insn 7 6 8 /usr/lib64/gcc/x86_64-suse-linux/4.5/include/emmintrin.h:65 (set
(reg:V2DF 68)
(vec_duplicate:V2DF (reg:DF 69))) 1501 {vec_dupv2df} (nil))
(insn 8 7 9 /usr/lib64/gcc/x86_64-suse-linux/4.5/include/emmintrin.h:65 (set
(reg:DF 69)
(mem/c/i:DF (plus:DI (reg/f:DI 54 virtual-stack-vars)
(const_int -8 [0xfffffffffffffff8])) [0 __F+0 S8 A64])) -1
(nil))
(insn 9 8 0 /usr/lib64/gcc/x86_64-suse-linux/4.5/include/emmintrin.h:65 (set
(reg:V2DF 64 [ D.6259 ])
(reg:V2DF 68)) -1 (nil))
whoops. We duplicate reg:DF 69 before setting it. That works ok in 4.4.
My bet is SSA expand.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |matz at gcc dot gnu dot org
Status|UNCONFIRMED |NEW
Component|inline-asm |middle-end
Ever Confirmed|0 |1
Keywords| |wrong-code
Priority|P3 |P1
Last reconfirmed|0000-00-00 00:00:00 |2010-01-27 16:16:46
date| |
Summary|SSE2 intrinsics miscompiled |[4.5 Regression] SSE2
|at -O0 -march=k8 |intrinsics miscompiled at -
| |O0 -march=k8
Target Milestone|--- |4.5.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42881