From bf1660a67066f9ad75d368466f5be15cc23a6ca1 Mon Sep 17 00:00:00 2001
From: Jeff Law <law@redhat.com>
Date: Mon, 10 Jun 2002 10:32:45 -0600
Subject: alias.c (static_reg_base_value): New to hold RTL for items allocated
 once per function for the aliasing code.

	* alias.c (static_reg_base_value): New to hold RTL for
	items allocated once per function for the aliasing code.
	(init_alias_once_per_function): Initialize static_reg_base_value.
	(init_alias_analysis): Avoid throw-away allocations of RTL by
	using pre-computed values in static_reg_base_value.
	* function.c (prepare_function_start): Call
	init_alias_once_per_function appropriately.
	* rtl.h (init_alias_once_per_function): Declare.
	* caller-save (init_caller_save): Restructure slightly to
	avoid lots of silly RTL generation.
	* expr.c (init_expr_once): Likewise.
	* reload1.c (reload_cse_regs_1): Allocate throw-away register
	RTL object here.  Pass it into children.
	(reload_cse_simplify_operands): Use passed-in register RTL
	object.
	(reload_cse_simplify): Pass through throw-away register
	RTL object.

From-SVN: r54442
---
 gcc/caller-save.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

(limited to 'gcc/caller-save.c')

diff --git a/gcc/caller-save.c b/gcc/caller-save.c
index 87a13dc..920bafd 100644
--- a/gcc/caller-save.c
+++ b/gcc/caller-save.c
@@ -115,6 +115,9 @@ init_caller_save ()
   rtx address;
   int i, j;
   enum machine_mode mode;
+  rtx savepat, restpat;
+  rtx test_reg, test_mem;
+  rtx saveinsn, restinsn;
 
   /* First find all the registers that we need to deal with and all
      the modes that they can have.  If we can't find a mode to use,
@@ -179,7 +182,17 @@ init_caller_save ()
     address = addr_reg;
 
   /* Next we try to form an insn to save and restore the register.  We
-     see if such an insn is recognized and meets its constraints.  */
+     see if such an insn is recognized and meets its constraints. 
+
+     To avoid lots of unnecessary RTL allocation, we construct all the RTL
+     once, then modify the memory and register operands in-place.  */
+
+  test_reg = gen_rtx_REG (VOIDmode, 0);
+  test_mem = gen_rtx_MEM (VOIDmode, address);
+  savepat = gen_rtx_SET (VOIDmode, test_mem, test_reg);
+  restpat = gen_rtx_SET (VOIDmode, test_reg, test_mem);
+  saveinsn = emit_insn (savepat);
+  restinsn = emit_insn (restpat);
 
   start_sequence ();
 
@@ -187,14 +200,14 @@ init_caller_save ()
     for (mode = 0 ; mode < MAX_MACHINE_MODE; mode++)
       if (HARD_REGNO_MODE_OK (i, mode))
         {
-	  rtx mem = gen_rtx_MEM (mode, address);
-	  rtx reg = gen_rtx_REG (mode, i);
-	  rtx savepat = gen_rtx_SET (VOIDmode, mem, reg);
-	  rtx restpat = gen_rtx_SET (VOIDmode, reg, mem);
-	  rtx saveinsn = emit_insn (savepat);
-	  rtx restinsn = emit_insn (restpat);
 	  int ok;
 
+	  /* Update the register number and modes of the register
+	     and memory operand.  */
+	  REGNO (test_reg) = i;
+	  PUT_MODE (test_reg, mode);
+	  PUT_MODE (test_mem, mode);
+
 	  reg_save_code[i][mode] = recog_memoized (saveinsn);
 	  reg_restore_code[i][mode] = recog_memoized (restinsn);
 
-- 
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