From 6bacc7b094be8ab0fff0a465298d14d298fc9d29 Mon Sep 17 00:00:00 2001
From: Nick Clifton <nickc@cambridge.redhat.com>
Date: Wed, 23 Jan 2002 11:04:56 +0000
Subject: [PATCH] Use an UNSPEC instead of a USE to prevent prologue/epilogue
insns from being deleted.
From-SVN: r49130
---
gcc/ChangeLog | 11 +++++++++++
gcc/config/arm/arm.c | 10 +++++-----
gcc/config/arm/arm.md | 14 ++++++++++++--
3 files changed, 28 insertions(+), 7 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f12b7ab8ef93..5c5da99da5a8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2002-01-23 Nick Clifton <nickc@cambridge.redhat.com>
+
+ * config/arm/arm.md (UNSPEC_PROLOGUE_USE): New unspec constant.
+ (prologue_use): New pattern.
+ * config/arm/arm.c (expand_prologue): Use gen_prologue_use in
+ preference to gen_rtx_USE.
+ (thumb_expand_prologue): Use gen_prologue_use in preference to
+ gen_rtx_USE.
+ (thumb_expand_epilogue): Use gen_prologue_use in preference to
+ gen_rtx_USE.
+
2002-01-23 Hans-Peter Nilsson <hp@bitrange.com>
* loop.c [!HAVE_prefetch] (CODE_FOR_prefetch): Define to 0.
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 04f06ae997df..567daa373128 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -8331,7 +8331,7 @@ arm_expand_prologue ()
emit_insn (gen_rtx_SET (SImode, ip_rtx, insn));
/* Add a USE to stop propagate_one_insn() from barfing. */
- emit_insn (gen_rtx_USE (VOIDmode, ip_rtx));
+ emit_insn (gen_prologue_use (ip_rtx));
}
}
@@ -8377,7 +8377,7 @@ arm_expand_prologue ()
then make sure that it does not get reused by the ce2 pass. */
if ((live_regs_mask & (1 << LR_REGNUM)) == 0)
{
- emit_insn (gen_rtx_USE (VOIDmode, gen_rtx_REG (SImode, LR_REGNUM)));
+ emit_insn (gen_prologue_use (gen_rtx_REG (SImode, LR_REGNUM)));
cfun->machine->lr_save_eliminated = 1;
}
}
@@ -10186,7 +10186,7 @@ thumb_expand_prologue ()
/* Save it by copying it into a high, scratch register. */
emit_insn (gen_movsi (spare, reg));
/* Add a USE to stop propagate_one_insn() from barfing. */
- emit_insn (gen_rtx_USE (VOIDmode, spare));
+ emit_insn (gen_prologue_use (spare));
/* Decrement the stack. */
emit_insn (gen_movsi (reg, GEN_INT (- amount)));
@@ -10200,7 +10200,7 @@ thumb_expand_prologue ()
analysis will not consider the restore redundant. The
register won't be used again in this function and isn't
restored by the epilogue. */
- emit_insn (gen_rtx_USE (VOIDmode, reg));
+ emit_insn (gen_prologue_use (reg));
}
else
{
@@ -10248,7 +10248,7 @@ thumb_expand_epilogue ()
/* Emit a USE (stack_pointer_rtx), so that
the stack adjustment will not be deleted. */
- emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
+ emit_insn (gen_prologue_use (stack_pointer_rtx));
if (current_function_profile || TARGET_NO_SCHED_PRO)
emit_insn (gen_blockage ());
diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
index 5f508dd83873..3646fe5890f6 100644
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -1,6 +1,6 @@
;;- Machine description for ARM for GNU compiler
-;; Copyright 1991, 1993, 1994, 1995, 1996, 1996, 1997, 1998, 1999, 2000, 2001
-;; Free Software Foundation, Inc.
+;; Copyright 1991, 1993, 1994, 1995, 1996, 1996, 1997, 1998, 1999, 2000,
+;; 2001, 2002 Free Software Foundation, Inc.
;; Contributed by Pieter `Tiggr' Schoenmakers (rcpieter@win.tue.nl)
;; and Martin Simmons (@harleqn.co.uk).
;; More major hacks by Richard Earnshaw (rearnsha@arm.com).
@@ -64,6 +64,11 @@
(UNSPEC_CLZ 5) ; `clz' instruction, count leading zeros (SImode):
; operand 0 is the result,
; operand 1 is the parameter.
+ (UNSPEC_PROLOGUE_USE 6) ; As USE insns are not meaningful after reload,
+ ; this unspec is used to prevent the deletion of
+ ; instructions setting registers for EH handling
+ ; and stack frame generation. Operand 0 is the
+ ; register to "use".
]
)
@@ -9187,3 +9192,8 @@
""
)
+(define_insn "prologue_use"
+ [(unspec:SI [(match_operand:SI 0 "register_operand" "")] UNSPEC_PROLOGUE_USE)]
+ ""
+ "%@ %0 needed for prologue"
+)
--
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