Re: [PATCH] lround for PowerPC

[Richard Biener <richard.guenther@gmail.com>]

On November 22, 2015 2:52:53 AM GMT+01:00, David Edelsohn <dje.gcc@gmail.com> wrote:
>PowerPC was missing a definition of the lroundMN pattern, which can be
>implemented with  VSX instructions available in Power7.  Below is a
>first draft.
>
>- David
>
>* config/rs6000/rs6000.md (*xsrdpidf2): New define_insn.
>(lrounddfdi2): New define_expand.
>
>diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
>index 8c53c40..eadbe1d 100644
>--- a/gcc/config/rs6000/rs6000.md
>+++ b/gcc/config/rs6000/rs6000.md
>@@ -77,6 +77,7 @@
>    UNSPEC_FRIN
>    UNSPEC_FRIP
>    UNSPEC_FRIZ
>+   UNSPEC_XSRDPI
>    UNSPEC_LD_MPIC              ; load_macho_picbase
>    UNSPEC_RELD_MPIC            ; re-load_macho_picbase
>    UNSPEC_MPIC_CORRECT         ; macho_correct_pic
>@@ -5245,6 +5246,27 @@
>   [(set_attr "type" "fp")
>    (set_attr "fp_type" "fp_addsub_<Fs>")])
>
>+(define_insn "*xsrdpidf2"
>+  [(set (match_operand:DF 0 "gpc_reg_operand" "=<Fv>")
>+       (unspec:DF [(match_operand:DF 1 "gpc_reg_operand" "<Fv>")]
>+                  UNSPEC_XSRDPI))]
>+  "TARGET_DF_FPR && TARGET_POPCNTD"
>+  "xsrdpi %0,%1"
>+  [(set_attr "type" "fp")])
>+
>+(define_expand "lrounddfdi2"
>+  [(set (match_dup 2)
>+       (unspec:DF [(match_operand:DF 1 "gpc_reg_operand" "<Fv>")]
>+                  UNSPEC_XSRDPI))
>+   (set (match_operand:DI 0 "gpc_reg_operand" "=d")
>+       (unspec:DI [(match_dup 2)]
>+                  UNSPEC_FCTID))]
>+  "TARGET_DF_FPR && TARGET_POPCNTD
>+   && flag_unsafe_math_optimizations && !flag_trapping_math"

Why unsafe-math?

Richard.

>+{
>+  operands[2] = gen_reg_rtx (DFmode);
>+})
>+
>; An UNSPEC is used so we don't have to support SImode in FP registers.
> (define_insn "stfiwx"
>   [(set (match_operand:SI 0 "memory_operand" "=Z")