For gcc 4.9, I intend to ensure that optabs.c can make automatic use of
[us]mul<mode>_highpart. There are plenty of targets that only implement
_highpart but not the widening pattern. But that's not something that
would be appropriate at this stage in the 4.8 cycle.
Whether this patch is appropriate for 4.8.0 is someone else's call, but
it's probably safe to queue it for 4.8.1.
r~
* config/rs6000/rs6000.md (smulditi3): New.
(umulditi3): New.
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index a4af648..b3db681 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -6326,6 +6326,34 @@
"mulhdu %0,%1,%2"
[(set_attr "type" "lmul")])
+(define_expand "mulditi3"
+ [(set (match_operand:TI 0 "gpc_reg_operand")
+ (mult:TI (sign_extend:TI (match_operand:DI 1 "gpc_reg_operand"))
+ (sign_extend:TI (match_operand:DI 2 "gpc_reg_operand"))))]
+ "TARGET_POWERPC64"
+{
+ rtx l = gen_reg_rtx (DImode), h = gen_reg_rtx (DImode);
+ emit_insn (gen_muldi3 (l, operands[1], operands[2]));
+ emit_insn (gen_smuldi3_highpart (h, operands[1], operands[2]));
+ emit_move_insn (gen_lowpart (DImode, operands[0]), l);
+ emit_move_insn (gen_highpart (DImode, operands[0]), h);
+ DONE;
+})
+
+(define_expand "umulditi3"
+ [(set (match_operand:TI 0 "gpc_reg_operand")
+ (mult:TI (zero_extend:TI (match_operand:DI 1 "gpc_reg_operand"))
+ (zero_extend:TI (match_operand:DI 2 "gpc_reg_operand"))))]
+ "TARGET_POWERPC64"
+{
+ rtx l = gen_reg_rtx (DImode), h = gen_reg_rtx (DImode);
+ emit_insn (gen_muldi3 (l, operands[1], operands[2]));
+ emit_insn (gen_umuldi3_highpart (h, operands[1], operands[2]));
+ emit_move_insn (gen_lowpart (DImode, operands[0]), l);
+ emit_move_insn (gen_highpart (DImode, operands[0]), h);
+ DONE;
+})
+
(define_insn "rotldi3"
[(set (match_operand:DI 0 "gpc_reg_operand" "=r,r")
(rotate:DI (match_operand:DI 1 "gpc_reg_operand" "r,r")
