[Mono-dev] [PATCH]: Use sparc 'sethi' in more cases.

[Zoltan Varga]

Hi,

This and the other patch is now in SVN.

           Zoltan

On Nov 4, 2007 12:15 AM, David Miller <davem at davemloft.net> wrote:
>
> The Sparc code generator is too strict in it's tests
> for when just a 'sethi' can be used to load a constant.
>
> 'sethi' loads the top 22-bits of a 32-bit register with the given
> constant value.
>
> This patch corrects the test, so that we use 1 instruction
> instead of 2 more often.
>
> 2007-11-03  David S. Miller  <davem at davemloft.net>
>
>         * sparc/sparc-codegen.h (sparc_set32, sparc_set): A plain sethi
>         can be used if the constant value only has the top 22 bits set.
>
> Index: mono/arch/sparc/sparc-codegen.h
> ===================================================================
> --- mono/arch/sparc/sparc-codegen.h     (revision 88629)
> +++ mono/arch/sparc/sparc-codegen.h     (working copy)
> @@ -855,7 +855,7 @@ typedef struct {
>         do {    \
>          if ((val) == 0) \
>              sparc_clr_reg((ins),(reg)); \
> -               else if (((guint32)(val) & 0x1fff) == 0)        \
> +               else if (((guint32)(val) & 0x3ff) == 0) \
>                         sparc_sethi((ins),(guint32)(val),(reg));        \
>                 else if (((gint32)(val) >= -4096) && ((gint32)(val) <= 4095))   \
>                         sparc_or_imm((ins),FALSE,sparc_g0,(gint32)(val),(reg)); \
> @@ -883,7 +883,8 @@ typedef struct {
>                 else if ((val >= -4096) && ((val) <= 4095))     \
>                         sparc_or_imm((ins),FALSE,sparc_g0,bottom_word,(reg));   \
>          else if ((val >= 0) && (val <= 4294967295L)) {   \
> -                       sparc_sethi((ins),bottom_word,(reg));   \
> +               sparc_sethi((ins),bottom_word,(reg));   \
> +               if (bottom_word & 0x3ff) \
>                         sparc_or_imm((ins),FALSE,(reg),bottom_word&0x3ff,(reg));        \
>          } \
>          else if ((val >= 0) && (val <= (1L << 44) - 1)) {  \
> @@ -913,7 +914,7 @@ typedef struct {
>         do {    \
>          if ((val) == 0) \
>              sparc_clr_reg((ins),(reg)); \
> -               else if (((guint32)(val) & 0x1fff) == 0)        \
> +               else if (((guint32)(val) & 0x3ff) == 0) \
>                         sparc_sethi((ins),(guint32)(val),(reg));        \
>                 else if (((gint32)(val) >= -4096) && ((gint32)(val) <= 4095))   \
>                         sparc_or_imm((ins),FALSE,sparc_g0,(gint32)(val),(reg)); \
> _______________________________________________
> Mono-devel-list mailing list
> Mono-devel-list at lists.ximian.com
> http://lists.ximian.com/mailman/listinfo/mono-devel-list
>