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From: miles@gnu.org
To: gcc-gnats@gcc.gnu.org
Subject: target/8052: NEC v850 has bogus default insn length
Date: Wed, 25 Sep 2002 19:36:00 -0000 [thread overview]
Message-ID: <20020926022639.D3D6A3721@mcspd15.ucom.lsi.nec.co.jp> (raw)
>Number: 8052
>Category: target
>Synopsis: NEC v850 has bogus default insn length
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: unassigned
>State: open
>Class: pessimizes-code
>Submitter-Id: net
>Arrival-Date: Wed Sep 25 19:36:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator: Miles Bader
>Release: 3.3 20020924 (experimental)
>Organization:
NEC
>Environment:
System: Linux mcspd15 2.4.18-ac3 #1 Wed Jul 3 14:28:04 JST 2002 i686 unknown unknown GNU/Linux
Architecture: i686
host: i386-pc-linux-gnu
build: i386-pc-linux-gnu
target: v850e-unknown-elf
configured with: /proj/soft2/uclinux/src/gcc/configure --prefix=/proj/soft2/uclinux/i386-pc-linux-gnu --cache-file=../config.cache --target=v850e-elf --host=i386-pc-linux-gnu --with-newlib
>Description:
The default insn-length in gcc/config/v850/v850.md is 200, which is
completely absurd, and has the effect of causing many branches around
`asm' statements to be long jumps (since gcc uses the default
insn-length to estimate the code-size of asm statements).
On the v850, many instructions are 2 bytes, and only one is >4 bytes,
so I've used a value of `4' instead for over a year, and it works great.
>How-To-Repeat:
>Fix:
Here's a patch:
2002-09-26 Miles Bader <miles@gnu.org>
* config/v850/v850.md ("length"): Change default value to 4.
Index: gcc/config/v850/v850.md
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/config/v850/v850.md,v
retrieving revision 1.20
diff -u -r1.20 v850.md
--- gcc/config/v850/v850.md 15 Sep 2002 18:24:07 -0000 1.20
+++ gcc/config/v850/v850.md 26 Sep 2002 02:15:22 -0000
@@ -33,7 +33,7 @@
;; The size of instructions in bytes.
(define_attr "length" ""
- (const_int 200))
+ (const_int 4))
(define_attr "long_calls" "yes,no"
(const (if_then_else (symbol_ref "TARGET_LONG_CALLS")
>Release-Note:
>Audit-Trail:
>Unformatted:
next reply other threads:[~2002-09-26 2:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-25 19:36 miles [this message]
2002-10-02 7:16 Jeff Law
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