------- Comment #1 from ramana at gcc dot gnu dot org 2009-12-29 10:35 -------
I can confirm this as a problem on the 4.4 branch and I can see this isn't a
problem on trunk .
.arch armv5te
.fpu softvfp
.eabi_attribute 20, 1
.eabi_attribute 21, 1
.eabi_attribute 23, 3
.eabi_attribute 24, 1
.eabi_attribute 25, 1
.eabi_attribute 26, 1
.eabi_attribute 30, 4
.eabi_attribute 18, 4
.code 16
.file "t.c"
.text
.align 1
.global test
.code 16
.thumb_func
.type test, %function
test:
ldr r3, .L4
mov r2, #0
str r2, [r3]
ldr r3, .L4+4
@ sp needed for prologue
ldr r2, [r3]
sub r3, r2, #1
sbc r2, r2, r3
ldr r3, .L4+8
lsl r2, r2, #1
strb r2, [r3]
bx lr
.L5:
.align 2
.L4:
.word outcnt
.word bool_var
.word outbuf
.size test, .-test
.ident "GCC: (GNU) 4.5.0 20091223 (experimental)"
--
ramana at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2009-12-29 10:35:21
date| |
Summary|Regression on dead-code- |[4.4 only] Regression on
|elimination: GCC 4.2.1 |dead-code-elimination: GCC
|generates better code than |4.2.1 generates better code
|4.4.0 |than 4.4.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42494
