diff mbox

[2/4,RS6000] PR69645, -ffixed-reg ignored

Message ID 20160321130648.GN22605@bubble.grove.modra.org
State New
Headers show

Commit Message

Alan Modra March 21, 2016, 1:06 p.m. UTC 
Treat -ffixed-reg as we do for global asm regs.  The only slightly
complicated part of this patch is that the rs6000 backend itself sets
fixed_regs[RS6000_PIC_OFFSET_TABLE_REGNUM] in some cases, which means
we can't simply test fixed_regs[] to determine whether a reg appeared
as -ffixed-reg.

	PR target/69645
	* config/rs6000/rs6000.c (fixed_reg_p): New function.
	(fixed_regs_p): Rename from global_regs_p.  Call fixed_reg_p.
	Update all uses.

Comments

David Edelsohn March 21, 2016, 2:50 p.m. UTC | #1 
On Mon, Mar 21, 2016 at 9:06 AM, Alan Modra <amodra@gmail.com> wrote:
> Treat -ffixed-reg as we do for global asm regs.  The only slightly
> complicated part of this patch is that the rs6000 backend itself sets
> fixed_regs[RS6000_PIC_OFFSET_TABLE_REGNUM] in some cases, which means
> we can't simply test fixed_regs[] to determine whether a reg appeared
> as -ffixed-reg.
>
>         PR target/69645
>         * config/rs6000/rs6000.c (fixed_reg_p): New function.
>         (fixed_regs_p): Rename from global_regs_p.  Call fixed_reg_p.
>         Update all uses.

Okay.

Thanks, David
diff mbox

Patch

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 0e570e4..99473bd 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -22996,17 +22996,34 @@  is_altivec_return_reg (rtx reg, void *xyes)
 }
 
 
-/* Look for user-defined global regs in the range FIRST to LAST-1.
-   We should not restore these, and so cannot use lmw or out-of-line
-   restore functions if there are any.  We also can't save them
-   (well, emit frame notes for them), because frame unwinding during
-   exception handling will restore saved registers.  */
+/* Return whether REG is a global user reg or has been specifed by
+   -ffixed-REG.  */
 
 static bool
-global_regs_p (unsigned first, unsigned last)
+fixed_reg_p (int reg)
+{
+  /* Ignore fixed_regs[RS6000_PIC_OFFSET_TABLE_REGNUM] when the
+     backend sets it, overriding anything the user might have given.  */
+  if (reg == RS6000_PIC_OFFSET_TABLE_REGNUM
+      && ((DEFAULT_ABI == ABI_V4 && flag_pic)
+	  || (DEFAULT_ABI == ABI_DARWIN && flag_pic)
+	  || (TARGET_TOC && TARGET_MINIMAL_TOC)))
+    return false;
+
+  return fixed_regs[reg];
+}
+
+/* Look for user-defined global regs or -ffixed-<reg> in the range
+   FIRST to LAST-1.  We should not restore these, and so cannot use
+   lmw or out-of-line restore functions if there are any.  We also
+   can't save them (well, emit frame notes for them), because frame
+   unwinding during exception handling will restore saved registers.  */
+
+static bool
+fixed_regs_p (unsigned first, unsigned last)
 {
   while (first < last)
-    if (global_regs[first++])
+    if (fixed_reg_p (first++))
       return true;
   return false;
 }
@@ -23037,7 +23054,7 @@  rs6000_savres_strategy (rs6000_stack_t *info,
       && !TARGET_POWERPC64
       && !(TARGET_SPE_ABI && info->spe_64bit_regs_used)
       && info->first_gp_reg_save < 31
-      && !global_regs_p (info->first_gp_reg_save, 32))
+      && !fixed_regs_p (info->first_gp_reg_save, 32))
     strategy |= SAVRES_MULTIPLE;
 
   if (crtl->calls_eh_return
@@ -23050,16 +23067,16 @@  rs6000_savres_strategy (rs6000_stack_t *info,
       /* The out-of-line FP routines use double-precision stores;
 	 we can't use those routines if we don't have such stores.  */
       || (TARGET_HARD_FLOAT && !TARGET_DOUBLE_FLOAT)
-      || global_regs_p (info->first_fp_reg_save, 64))
+      || fixed_regs_p (info->first_fp_reg_save, 64))
     strategy |= SAVE_INLINE_FPRS | REST_INLINE_FPRS;
 
   if (info->first_gp_reg_save == 32
       || (!(strategy & SAVRES_MULTIPLE)
-	  && global_regs_p (info->first_gp_reg_save, 32)))
+	  && fixed_regs_p (info->first_gp_reg_save, 32)))
     strategy |= SAVE_INLINE_GPRS | REST_INLINE_GPRS;
 
   if (info->first_altivec_reg_save == LAST_ALTIVEC_REGNO + 1
-      || global_regs_p (info->first_altivec_reg_save, LAST_ALTIVEC_REGNO + 1))
+      || fixed_regs_p (info->first_altivec_reg_save, LAST_ALTIVEC_REGNO + 1))
     strategy |= SAVE_INLINE_VRS | REST_INLINE_VRS;
 
   /* Define cutoff for using out-of-line functions to save registers.  */