http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54855
--- Comment #3 from Marc Glisse <glisse at gcc dot gnu.org> 2012-10-12 17:08:20
UTC ---
The following patch gives this loop:
.L7:
subsd %xmm0, %xmm1
subl $1, %eax
addpd %xmm1, %xmm1
jne .L7
I guess I should add the same for mul and div at the same time, but I don't
know if it is the right approach.
--- config/i386/sse.md (revision 192405)
+++ config/i386/sse.md (working copy)
@@ -812,20 +812,38 @@
(const_int 1)))]
"TARGET_SSE"
"@
<plusminus_mnemonic><ssescalarmodesuffix>\t{%2, %0|%0, %2}
v<plusminus_mnemonic><ssescalarmodesuffix>\t{%2, %1, %0|%0, %1, %2}"
[(set_attr "isa" "noavx,avx")
(set_attr "type" "sseadd")
(set_attr "prefix" "orig,vex")
(set_attr "mode" "<ssescalarmode>")])
+(define_insn "*sse2_vm<plusminus_insn>v2df3"
+ [(set (match_operand:V2DF 0 "register_operand" "=x,x")
+ (vec_concat:V2DF
+ (plusminus:DF
+ (vec_select:DF
+ (match_operand:V2DF 1 "register_operand" "0,x")
+ (parallel [(const_int 0)]))
+ (match_operand:DF 2 "nonimmediate_operand" "xm,xm"))
+ (vec_select:DF (match_dup 1) (parallel [(const_int 1)]))))]
+ "TARGET_SSE2"
+ "@
+ <plusminus_mnemonic>sd\t{%2, %0|%0, %2}
+ v<plusminus_mnemonic>sd\t{%2, %1, %0|%0, %1, %2}"
+ [(set_attr "isa" "noavx,avx")
+ (set_attr "type" "sseadd")
+ (set_attr "prefix" "orig,vex")
+ (set_attr "mode" "DF")])
+
(define_expand "mul<mode>3"
[(set (match_operand:VF 0 "register_operand")
(mult:VF
(match_operand:VF 1 "nonimmediate_operand")
(match_operand:VF 2 "nonimmediate_operand")))]
"TARGET_SSE"
"ix86_fixup_binary_operands_no_copy (MULT, <MODE>mode, operands);")
(define_insn "*mul<mode>3"
[(set (match_operand:VF 0 "register_operand" "=x,x")
