Hello, On Tue, Apr 08, 2014 at 07:06:58PM -0500, Pat Haugen wrote: > The following patch improves the code generated for TImode add/sub so > that we now generate a 2 insn sequence which makes use of the carry bit.
> +/* { dg-do compile { target { powerpc*-*-* && lp64 } } } */ > +/* { dg-skip-if "" { powerpc*-*-darwin* } { "*" } { "" } } */ Please leave out the default arguments. Why does this need skipping on Darwin? > +;; Define the TImode operations that can be done in a small number > +;; of instructions. The & constraints are to prevent the register > +;; allocator from allocating registers that overlap with the inputs > +;; (for example, having an input in 7,8 and an output in 6,7). We > +;; also allow for the output being the same as one of the inputs. > + > +(define_insn "addti3" > + [(set (match_operand:TI 0 "gpc_reg_operand" "=&r,&r,r,r") > + (plus:TI (match_operand:TI 1 "gpc_reg_operand" "%r,r,0,0") > + (match_operand:TI 2 "reg_or_short_operand" "r,I,r,I")))] > + "TARGET_POWERPC64" That's not the correct condition: the carry bit is set based on the 32-bit carry in 32-bit mode, so the condition has to be TARGET_64BIT. The adddi3 pattern has !TARGET_POWERPC64 since a 64-bit addition can be done without addc on a 64-bit machine, no matter what mode the CPU is in. > + "* > +{ Might as well leave out this stuff on new code, just use the braces :-) Segher