From: Jeff Law <law@redhat.com>
Date: Thu, 4 Nov 2010 13:15:33 +0000 (-0600)
Subject: ira.c (validate_equiv_mem): Remove code to avoid invalidation of readonly memory... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=a22265a4f9303a025c5291037d74f167a7b2590d;p=gcc.git

ira.c (validate_equiv_mem): Remove code to avoid invalidation of readonly memory equivalances for...

	* ira.c (validate_equiv_mem): Remove code to avoid invalidation
	of readonly memory equivalances for const/pure calls.

From-SVN: r166309
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a2e1cc88391..c5fe9b290bd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-04  Jeff Law  <law@redhat.com>
+
+	* ira.c (validate_equiv_mem): Remove code to avoid invalidation
+	of readonly memory equivalances for const/pure calls.
+
 2010-11-04  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/45733
diff --git a/gcc/ira.c b/gcc/ira.c
index e84230e1c3e..d37247f55b1 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -1915,8 +1915,12 @@ validate_equiv_mem (rtx start, rtx reg, rtx memref)
       if (find_reg_note (insn, REG_DEAD, reg))
 	return 1;
 
-      if (CALL_P (insn) && ! MEM_READONLY_P (memref)
-	  && ! RTL_CONST_OR_PURE_CALL_P (insn))
+      /* This used to ignore readonly memory and const/pure calls.  The problem
+	 is the equivalent form may reference a pseudo which gets assigned a
+	 call clobbered hard reg.  When we later replace REG with its
+	 equivalent form, the value in the call-clobbered reg has been
+	 changed and all hell breaks loose.  */
+      if (CALL_P (insn))
 	return 0;
 
       note_stores (PATTERN (insn), validate_equiv_mem_from_store, NULL);