http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51524
Uros Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2011-12-13
Component|target |testsuite
Ever Confirmed|0 |1
--- Comment #1 from Uros Bizjak <ubizjak at gmail dot com> 2011-12-13 14:02:33
UTC ---
Actually, not a bug but problem with the testcase.
Previously, %edx was allocated for temporary, resulting in:
gen_mulx:
.LFB30:
.cfi_startproc
#(insn:TI 20 4 23 2 (set (reg/v:SI 1 dx [orig:64 b ] [64])
# (mem/c/i:SI (plus:SI (reg/f:SI 7 sp)
# (const_int 8 [0x8])) [2 b+0 S4 A32])) bmi2-mulx32-1.c:24 64
{*movsi_internal}
# (expr_list:REG_EQUIV (mem/c/i:SI (plus:SI (reg/f:SI 7 sp)
# (const_int 8 [0x8])) [2 b+0 S4 A32])
# (nil)))
movl 8(%esp), %edx # 20 *movsi_internal/1 [length = 4]
#(insn:TI 23 20 17 2 (parallel [
# (set (reg:SI 0 ax [65])
# (mult:SI (reg/v:SI 1 dx [orig:64 b ] [64])
# (mem/c/i:SI (plus:SI (reg/f:SI 7 sp)
# (const_int 4 [0x4])) [2 a+0 S4 A32])))
# (set (reg:SI 1 dx [+4 ])
# (truncate:SI (lshiftrt:DI (mult:DI (zero_extend:DI (reg/v:SI 1
dx [orig:64 b ] [64]))
# (zero_extend:DI (mem/c/i:SI (plus:SI (reg/f:SI 7
sp)
# (const_int 4 [0x4])) [2 a+0 S4 A32])))
# (const_int 32 [0x20]))))
# ]) bmi2-mulx32-1.c:24 337 {*bmi2_umulsidi3_1}
# (nil))
mulx 4(%esp), %eax, %edx # 23 *bmi2_umulsidi3_1 [length = 7]
But now, %eax gets allocated as temporary, resulting in:
gen_mulx:
.LFB30:
.cfi_startproc
#(insn:TI 20 4 9 2 (set (reg/v:SI 0 ax [orig:64 b ] [64])
# (mem/c/i:SI (plus:SI (reg/f:SI 7 sp)
# (const_int 8 [0x8])) [2 b+0 S4 A32])) bmi2-mulx32-1.c:24 64
{*movsi_internal}
# (expr_list:REG_EQUIV (mem/c/i:SI (plus:SI (reg/f:SI 7 sp)
# (const_int 8 [0x8])) [2 b+0 S4 A32])
# (nil)))
movl 8(%esp), %eax # 20 *movsi_internal/1 [length = 4]
#(insn:TI 9 20 17 2 (parallel [
# (set (reg:DI 0 ax [65])
# (mult:DI (zero_extend:DI (reg/v:SI 0 ax [orig:64 b ] [64]))
# (zero_extend:DI (mem/c/i:SI (plus:SI (reg/f:SI 7 sp)
# (const_int 4 [0x4])) [2 a+0 S4 A32]))))
# (clobber (reg:CC 17 flags))
# ]) bmi2-mulx32-1.c:24 338 {*umulsidi3_1}
# (expr_list:REG_UNUSED (reg:CC 17 flags)
# (nil)))
mull 4(%esp) # 9 *umulsidi3_1/1 [length = 4]
(The latter version is IMO even better in this case).
A testcase should be fixed to force bmi2 alternative in:
(define_insn "*umul<mode><dwi>3_1"
[(set (match_operand:<DWI> 0 "register_operand" "=A,r")
(mult:<DWI>
(zero_extend:<DWI>
(match_operand:DWIH 1 "nonimmediate_operand" "%0,d"))
(zero_extend:<DWI>
(match_operand:DWIH 2 "nonimmediate_operand" "rm,rm"))))
(clobber (reg:CC FLAGS_REG))]
"!(MEM_P (operands[1]) && MEM_P (operands[2]))"
"@
mul{<imodesuffix>}\t%2
#"
[(set_attr "isa" "*,bmi2")
...
