From fc0cc704f6899e6f13f244d5530fe3e002f1d997 Mon Sep 17 00:00:00 2001
From: ebotcazou <ebotcazou@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue, 1 Feb 2005 07:22:19 +0000
Subject: [PATCH] Patch from Richard Sandiford <rsandifo@redhat.com>
* reload1.c (choose_reload_regs): Prevent the find_equiv_reg() code from
inheriting a subreg equivalence with a non-spill register.
* tree.h (DECL_FUNCTION_CODE): Document that it is overloaded.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@94529 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/ChangeLog | 8 ++++++++
gcc/reload1.c | 9 +++++++++
gcc/tree.h | 6 ++++--
3 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ce0422c9323b..343125f41133 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2005-02-01 Eric Botcazou <ebotcazou@libertysurf.fr>
+
+ Patch from Richard Sandiford <rsandifo@redhat.com>
+ * reload1.c (choose_reload_regs): Prevent the find_equiv_reg() code
+ from inheriting a subreg equivalence with a non-spill register.
+
+ * tree.h (DECL_FUNCTION_CODE): Document that it is overloaded.
+
2005-02-01 Alexandre Oliva <aoliva@redhat.com>
* config/frv/frv.c (movcc_fp_destination_operand): New.
diff --git a/gcc/reload1.c b/gcc/reload1.c
index 7961c99b9c46..d4141be5aee2 100644
--- a/gcc/reload1.c
+++ b/gcc/reload1.c
@@ -5589,6 +5589,15 @@ choose_reload_regs (struct insn_chain *chain)
gcc_assert (GET_CODE (equiv) == SUBREG);
regno = subreg_regno (equiv);
equiv = gen_rtx_REG (rld[r].mode, regno);
+ /* If we choose EQUIV as the reload register, but the
+ loop below decides to cancel the inheritance, we'll
+ end up reloading EQUIV in rld[r].mode, not the mode
+ it had originally. That isn't safe when EQUIV isn't
+ available as a spill register since its value might
+ still be live at this point. */
+ for (i = regno; i < regno + (int) rld[r].nregs; i++)
+ if (TEST_HARD_REG_BIT (reload_reg_unavailable, i))
+ equiv = 0;
}
}
diff --git a/gcc/tree.h b/gcc/tree.h
index a4c590b476ab..10012e406fd3 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -2000,8 +2000,10 @@ struct tree_binfo GTY (())
that describes the status of this function. */
#define DECL_STRUCT_FUNCTION(NODE) (FUNCTION_DECL_CHECK (NODE)->decl.u2.f)
-/* For FUNCTION_DECL, if it is built-in,
- this identifies which built-in operation it is. */
+/* For FUNCTION_DECL, if it is built-in, this identifies which built-in
+ operation it is. Note, however, that this field is overloaded, with
+ DECL_BUILT_IN_CLASS as the discriminant, so the latter must always be
+ checked before any access to the former. */
#define DECL_FUNCTION_CODE(NODE) (FUNCTION_DECL_CHECK (NODE)->decl.u1.f)
/* The DECL_VINDEX is used for FUNCTION_DECLS in two different ways.
--
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