-fno-strength-reduce flag patch

Paul Rusty Russell (Paul.Russell@rustcorp.com.au)
Mon, 15 Sep 1997 23:18:31 +1000


Hi all,

I notice that -fno-strength-reduce is still specified for
CFLAGS in i386/Makefile. I believe this optimisation bug was fixed in
gcc 2.7.2.1.

This (ugly) one-line patch to 2.1.55 re-enables strength
reduction for gcc 2.7.2.x, 2.[89], [3-9], etc - should be futureproof
enough for a few years: at worst it will enable -fno-strength-reduce
again when gcc 2.10 is released...

*** linux/arch/i386/Makefile.~1~ Fri May 16 09:48:01 1997
--- linux/arch/i386/Makefile Sun Sep 14 19:04:31 1997
***************
*** 23,29 ****
LDFLAGS=-e stext
LINKFLAGS =-T $(TOPDIR)/arch/i386/vmlinux.lds $(LDFLAGS)

! CFLAGS := $(CFLAGS) -pipe -fno-strength-reduce

ifdef CONFIG_M386
CFLAGS := $(CFLAGS) -m386 -DCPU=386
--- 23,29 ----
LDFLAGS=-e stext
LINKFLAGS =-T $(TOPDIR)/arch/i386/vmlinux.lds $(LDFLAGS)

! CFLAGS := $(CFLAGS) -pipe $(shell $(CC) -v 2>&1|egrep -q 'version (2\.7\.2\.[0-9]|2\.7\.[3-9]|2\.[8-9]|[3-9]\.)' || echo -fno-strength-reduce)

ifdef CONFIG_M386
CFLAGS := $(CFLAGS) -m386 -DCPU=386

Enjoy,
Paul.

--
 .sig lost in the mail.