Apparently, the compiler likes -floop-optimize2 very much and does
not want it to be switched off:
$ gcc -O1 -fno-loop-optimize -fno-loop-optimize2 -S -fverbose-asm example.c
$ cat example.s
.file "example.c"
.pred.safe_across_calls p1-p5,p16-p63
// GNU C version 4.0.0 20050130 (experimental) (ia64-unknown-linux-gnu)
// compiled by GNU C version 4.0.0 20050130 (experimental).
// GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
// options passed: -auxbase -O1 -fno-loop-optimize -fno-loop-optimize2
// -fverbose-asm
// options enabled: -falign-loops -fargument-alias -fbranch-count-reg
// -fcommon -fcprop-registers -fdefer-pop -feliminate-unused-debug-types
// -ffunction-cse -fgcse-lm -fguess-branch-probability -fident
// -fif-conversion -fif-conversion2 -fivopts -fkeep-static-consts
// -fleading-underscore -floop-optimize2 -fmath-errno -fmerge-constants
// -fomit-frame-pointer -fpeephole -freg-struct-return -fsched-interblock
// -fsched-spec -fsched-stalled-insns-dep -fsplit-ivs-in-unroller
// -ftrapping-math -ftree-ccp -ftree-ch -ftree-copyrename -ftree-dce
// -ftree-dominator-opts -ftree-dse -ftree-fre -ftree-loop-im
// -ftree-loop-ivcanon -ftree-loop-optimize -ftree-lrs -ftree-sra
// -ftree-ter -funwind-tables -fverbose-asm -fzero-initialized-in-bss
// -mgnu-as -mgnu-ld -minline-float-divide-max-throughput -mdwarf2-asm
// -mtune=itanium2
.text
.align 16
.global main#
.proc main#
main:
.prologue
.body
mov r8 = r0 // <result>,
br.ret.sptk.many b0 //
;;
.endp main#
.ident "GCC: (GNU) 4.0.0 20050130 (experimental)"
$ gcc -dumpmachine
ia64-unknown-linux-gnu
--
Summary: -fno-loop-optimize2 does not work
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: driver
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: Thomas dot Koenig at online dot de
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19825
