------- Comment #8 from rguenth at gcc dot gnu dot org 2010-03-27 16:38 -------
Just to clarify, the issue is that
(insn 6 5 7 2 t.i:2 (set (reg:DF 21 xmm0)
(float_extend:DF (mem/u/c/i:SF (symbol_ref/u:SI ("*.LC0") [flags 0x2])
[0 S4 A32]))) 99 {*extendsfdf2_i387} (expr_list:REG_EQUAL (const_double:DF
-2147483648 [0x80000000] 1.0e+0 [0x0.8p+1])
(nil)))
with
(define_insn "*extendsfdf2_i387"
[(set (match_operand:DF 0 "nonimmediate_operand" "=f,m")
(float_extend:DF (match_operand:SF 1 "nonimmediate_operand" "fm,f")))]
"TARGET_80387"
"* return output_387_reg_move (insn, operands);"
[(set_attr "type" "fmov")
(set_attr "mode" "SF,XF")])
requires a reload for the x87 register to xmm0 move. The
(define_insn "*extendsfdf2_sse"
[(set (match_operand:DF 0 "nonimmediate_operand" "=x")
(float_extend:DF (match_operand:SF 1 "nonimmediate_operand" "xm")))]
"TARGET_SSE2 && TARGET_SSE_MATH"
"%vcvtss2sd\t{%1, %d0|%d0, %1}"
[(set_attr "type" "ssecvt")
(set_attr "prefix" "maybe_vex")
(set_attr "mode" "DF")])
alternative is not enabled, both because just -msse is supplied and
SSE math is not enabled. But I fail to see why we can't go through
unaligned memory if the user asks us to - which puts the finger
at the assert that triggers (and maybe reload if it can not properly
deal with less aligned stack slots).
Testcase that doesn't need -msseregparm:
extern void __attribute__((sseregparm)) bar(double);
void foo() { bar(1.0); }
commenting the assert yields odd
foo:
pushl %ebp
movl %esp, %ebp
subl $8, %esp
fld1
fstpl -8(%ebp)
movlps -8(%ebp), %xmm0
call bar
leave
ret
obviously w/o -msse2 there's no movsd, thus the odd code.
And the handed out secondary memory has correct alignment:
insn 6 5 11 2 t.i:2 (set (reg:DF 8 st)
(float_extend:DF (mem/u/c/i:SF (symbol_ref/u:SI ("*.LC0") [flags 0x2])
[0 S4 A32]))) 99 {*extendsfdf2_i387} (expr_list:REG_EQUAL (const_double:DF
-2147483648 [0x80000000] 1.0e+0 [0x0.8p+1])
(nil)))
(insn 11 6 12 2 t.i:2 (set (mem/c:DF (plus:SI (reg/f:SI 6 bp)
(const_int -8 [0xfffffff8])) [0 S8 A32])
(reg:DF 8 st)) 74 {*movdf_nointeger} (nil))
(insn 12 11 7 2 t.i:2 (set (reg:DF 21 xmm0)
(mem/c:DF (plus:SI (reg/f:SI 6 bp)
(const_int -8 [0xfffffff8])) [0 S8 A32])) 74 {*movdf_nointeger}
(nil))
(call_insn 7 12 10 2 t.i:2 (call (mem:QI (symbol_ref:SI ("bar") [flags 0x41]
<function_decl 0xb77a4c80 bar>) [0 S1 A8])
(const_int 0 [0x0])) 484 {*call_0} (nil)
(expr_list:REG_DEP_TRUE (use (reg:DF 21 xmm0))
(nil)))
so why are we using assign_stack_local here and not assign_stack_local_1 (...,
true)? Here, at
#3 0x0846d729 in get_secondary_mem (x=0xb77a96f0, mode=DFmode, opnum=0,
type=RELOAD_FOR_OUTPUT) at /home/richard/src/trunk/gcc/reload.c:608
608 = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
(gdb) l
603 {
604 #ifdef SECONDARY_MEMORY_NEEDED_RTX
605 secondary_memlocs[(int) mode] = SECONDARY_MEMORY_NEEDED_RTX
(mode);
606 #else
607 secondary_memlocs[(int) mode]
608 = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
609 #endif
610 }
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Priority|P3 |P2
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43546
