Support using multiple registers to hold the frame pointer

When multiple hard registers are required to hold the frame pointer,
ensure that the registers after the first are marked as non-allocatable,
live and eliminable as well.

2019-11-07  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* ira.c (setup_alloc_regs): Setup no_unit_alloc_regs for
	frame pointer in multiple registers.
	(ira_setup_eliminable_regset): Setup eliminable_regset,
	ira_no_alloc_regs and regs_ever_live for frame pointer in
	multiple registers.

From-SVN: r277895

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c3dc5b333dfdbbaa7910f8b7abb87d01eb9c93c2..f5ef703927dd36c2db0629698d1694b3b265ab12 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2019-11-07  Kwok Cheung Yeung  <kcy@codesourcery.com>
+
+       * ira.c (setup_alloc_regs): Setup no_unit_alloc_regs for
+       frame pointer in multiple registers.
+       (ira_setup_eliminable_regset): Setup eliminable_regset,
+       ira_no_alloc_regs and regs_ever_live for frame pointer in
+       multiple registers.
+
 2019-11-06  Kelvin Nilsen  <kelvin@gcc.gnu.org>
 
        * config/rs6000/vsx.md (xxswapd_<mode>): Add support for V2DF and

diff --git a/gcc/ira.c b/gcc/ira.c
index 9f8da67539cfca3720cdcd7ac8342332d2ec5626..5df995364dd94a33c5dd6fa6d7a011a636e240d8 100644 (file)
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -515,7 +515,8 @@ setup_alloc_regs (bool use_hard_frame_p)
 #endif
   no_unit_alloc_regs = fixed_nonglobal_reg_set;
   if (! use_hard_frame_p)
-    SET_HARD_REG_BIT (no_unit_alloc_regs, HARD_FRAME_POINTER_REGNUM);
+    add_to_hard_reg_set (&no_unit_alloc_regs, Pmode,
+                        HARD_FRAME_POINTER_REGNUM);
   setup_class_hard_regs ();
 }
 
@@ -2248,6 +2249,7 @@ ira_setup_eliminable_regset (void)
 {
   int i;
   static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
+  int fp_reg_count = hard_regno_nregs (HARD_FRAME_POINTER_REGNUM, Pmode);
 
   /* Setup is_leaf as frame_pointer_required may use it.  This function
      is called by sched_init before ira if scheduling is enabled.  */
@@ -2276,7 +2278,8 @@ ira_setup_eliminable_regset (void)
        frame pointer in LRA.  */
 
   if (frame_pointer_needed)
-    df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM, true);
+    for (i = 0; i < fp_reg_count; i++)
+      df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM + i, true);
     
   ira_no_alloc_regs = no_unit_alloc_regs;
   CLEAR_HARD_REG_SET (eliminable_regset);
@@ -2306,17 +2309,21 @@ ira_setup_eliminable_regset (void)
     }
   if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
     {
-      if (!TEST_HARD_REG_BIT (crtl->asm_clobbers, HARD_FRAME_POINTER_REGNUM))
-       {
-         SET_HARD_REG_BIT (eliminable_regset, HARD_FRAME_POINTER_REGNUM);
-         if (frame_pointer_needed)
-           SET_HARD_REG_BIT (ira_no_alloc_regs, HARD_FRAME_POINTER_REGNUM);
-       }
-      else if (frame_pointer_needed)
-       error ("%s cannot be used in %<asm%> here",
-              reg_names[HARD_FRAME_POINTER_REGNUM]);
-      else
-       df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM, true);
+      for (i = 0; i < fp_reg_count; i++)
+       if (!TEST_HARD_REG_BIT (crtl->asm_clobbers,
+                               HARD_FRAME_POINTER_REGNUM + i))
+         {
+           SET_HARD_REG_BIT (eliminable_regset,
+                             HARD_FRAME_POINTER_REGNUM + i);
+           if (frame_pointer_needed)
+             SET_HARD_REG_BIT (ira_no_alloc_regs,
+                               HARD_FRAME_POINTER_REGNUM + i);
+         }
+       else if (frame_pointer_needed)
+         error ("%s cannot be used in %<asm%> here",
+                reg_names[HARD_FRAME_POINTER_REGNUM + i]);
+       else
+         df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM + i, true);
     }
 }