Hi,
On Sun, Nov 08, 2015 at 07:36:16PM -0500, Michael Meissner wrote:
> [gcc/testsuite]
> * lib/target-supports.exp (check_p9vector_hw_available): Add
> checks for power9 availability.
> (check_effective_target_powerpc_p9vector_ok): Likewise.
It's probably better not to use this for modulo; it is confusing and if
you'll later need to untangle it it is much more work.
> +/* { dg-do compile { target { powerpc*-*-* && lp64 } } } */
> +/* { dg-skip-if "" { powerpc*-*-darwin* } { "*" } { "" } } */
Lose this line? If Darwin cannot support modulo, the next line will
catch that.
+/* { dg-require-effective-target powerpc_p9vector_ok } */
> +/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } {
> "-mcpu=power9" } } */
> +/* { dg-options "-mcpu=power9 -O3" } */
Is -O3 needed? Why won't -O2 work?
> +proc check_p9vector_hw_available { } {
> + return [check_cached_effective_target p9vector_hw_available {
> + # Some simulators are known to not support VSX/power8 instructions.
> + # For now, disable on Darwin
> + if { [istarget powerpc-*-eabi] || [istarget powerpc*-*-eabispe] ||
> [istarget *-*-darwin*]} {
Long line.
> Index: gcc/config/rs6000/rs6000.md
> ===================================================================
> --- gcc/config/rs6000/rs6000.md (revision 229972)
> +++ gcc/config/rs6000/rs6000.md (working copy)
> @@ -2885,9 +2885,9 @@ (define_insn_and_split "*div<mode>3_sra_
> (set_attr "cell_micro" "not")])
>
> (define_expand "mod<mode>3"
> - [(use (match_operand:GPR 0 "gpc_reg_operand" ""))
> - (use (match_operand:GPR 1 "gpc_reg_operand" ""))
> - (use (match_operand:GPR 2 "reg_or_cint_operand" ""))]
> + [(set (match_operand:GPR 0 "gpc_reg_operand" "")
> + (mod:GPR (match_operand:GPR 1 "gpc_reg_operand" "")
> + (match_operand:GPR 2 "reg_or_cint_operand" "")))]
You could delete the empty constraint strings while you're at it.
> +;; On machines with modulo support, do a combined div/mod the old fashioned
> +;; method, since the multiply/subtract is faster than doing the mod
> instruction
> +;; after a divide.
You can instead have a "divmod" insn that is split to either of div, mod,
or div+mul+sub depending on which of the outputs is unused. Peepholes
do not get all cases.
This can be a later improvement of course.
Segher
