------- Comment #1 from pinskia at gcc dot gnu dot org 2006-08-11 05:52 -------
The problem is obvious from the RTL:
(insn:TI 47 7 48 (set (reg:CCFP 17 flags)
(compare:CCFP (reg/v:SF 22 xmm1 [orig:59 a ] [59])
(reg/v:SF 21 xmm0 [orig:60 b ] [60]))) 23 {*cmpfp_i_sse}
(insn_list:REG_DEP_OUTPUT 46 (insn_list:REG_DEP_TRUE 6 (insn_list:REG_DEP_TRUE
7 (nil))))
(nil))
(insn 48 47 43 (set (strict_low_part (reg:QI 0 ax [62]))
(unlt:QI (reg:CCFP 17 flags)
(const_int 0 [0x0]))) 347 {*setcc_2} (insn_list:REG_DEP_TRUE 47
(insn_list:REG_DEP_TRUE 46 (nil)))
(expr_list:REG_DEAD (reg:CCFP 17 flags)
(nil)))
(insn 43 48 44 (parallel [
(set (reg:SI 1 dx [64])
(const_int 0 [0x0]))
(clobber (reg:CC 17 flags))
]) 32 {*movsi_xor} (insn_list:REG_DEP_ANTI 48 (insn_list:REG_DEP_OUTPUT
47 (nil)))
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil)))
(insn:TI 44 43 45 (set (reg:CCFP 17 flags)
(compare:CCFP (reg/v:SF 22 xmm1 [orig:59 a ] [59])
(reg/v:SF 21 xmm0 [orig:60 b ] [60]))) 23 {*cmpfp_i_sse}
(insn_list:REG_DEP_ANTI 48 (insn_list:REG_DEP_OUTPUT 43
(insn_list:REG_DEP_OUTPUT 47 (insn_list:REG_DEP_TRUE 6 (insn_list:REG_DEP_TRUE
7 (nil))))))
(expr_list:REG_DEAD (reg/v:SF 22 xmm1 [orig:59 a ] [59])
(expr_list:REG_DEAD (reg/v:SF 21 xmm0 [orig:60 b ] [60])
(nil))))
(insn 45 44 18 (set (strict_low_part (reg:QI 1 dx [64]))
(uneq:QI (reg:CCFP 17 flags)
(const_int 0 [0x0]))) 347 {*setcc_2} (insn_list:REG_DEP_TRUE 44
(insn_list:REG_DEP_TRUE 43 (nil)))
(expr_list:REG_DEAD (reg:CCFP 17 flags)
(nil)))
But the question is xor really setting the flags?
Maybe even just getting the expansion of setting the int.
Anyways here is a work around:
int test(float a, float b)
{
unsigned char lt = a < b;
unsigned char eq = a == b;
unsigned char a1 = (lt + eq);
return a1;
}
Using unsigned char and a temp variable removes the problem of zero extending
the grabbing of the flags.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2006-08-11 05:52:26
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28691
