Patchwork patch to fix a bug in LRA hard reg splitting

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Submitter Vladimir Makarov
Date June 28, 2013, 7:47 p.m.
Message ID <51CDE86C.5090505@redhat.com>
Download mbox | patch
Permalink /patch/255653/
State New
Headers show

Comments

Vladimir Makarov - June 28, 2013, 7:47 p.m.
On 13-06-27 12:22 PM, Vladimir Makarov wrote:
> The following patch fixes a LRA bug for some experimental target.
> Sorry, there is no a test case and the bug can not be reproduced by
> other people until the target is made public.
>
>
Here is one more fix for another hard reg splitting bug.

The patch was successfully bootstrapped and tested on x86/x86-64.

Committed as rev. 200553.

2013-06-28  Vladimir Makarov  <vmakarov@redhat.com>

         * lra-constraints.c (need_for_split_p): Check call used hard regs
         living through calls.

Patch

Index: lra-constraints.c
===================================================================
--- lra-constraints.c	(revision 200552)
+++ lra-constraints.c	(working copy)
@@ -4201,6 +4201,15 @@  need_for_split_p (HARD_REG_SET potential
 	   && (regno >= FIRST_PSEUDO_REGISTER
 	       || ! TEST_HARD_REG_BIT (eliminable_regset, hard_regno))
 	   && ! TEST_HARD_REG_BIT (lra_no_alloc_regs, hard_regno)
+	   /* Don't split call clobbered hard regs living through
+	      calls, otherwise we might have a check problem in the
+	      assign sub-pass as in the most cases (exception is a
+	      situation when lra_risky_transformations_p value is
+	      true) the assign pass assumes that all pseudos living
+	      through calls are assigned to call saved hard regs.  */
+	   && (regno >= FIRST_PSEUDO_REGISTER
+	       || ! TEST_HARD_REG_BIT (call_used_reg_set, regno)
+	       || usage_insns[regno].calls_num == calls_num)
 	   /* We need at least 2 reloads to make pseudo splitting
 	      profitable.  We should provide hard regno splitting in
 	      any case to solve 1st insn scheduling problem when
@@ -4799,7 +4808,7 @@  inherit_in_ebb (rtx head, rtx tail)
 		     usage_insns invalidation.  */
 		  if ((dst_regno < FIRST_PSEUDO_REGISTER
 		       || reg_renumber[dst_regno] >= 0)
-		    && ! reg->subreg_p && reg->type != OP_IN)
+		      && ! reg->subreg_p && reg->type != OP_IN)
 		    {
 		      HARD_REG_SET s;