[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #8 from jakub at gcc dot gnu dot org 2007-05-30 13:32 --- Subject: Bug 29382 Author: jakub Date: Wed May 30 13:32:34 2007 New Revision: 125182 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=125182 Log: PR bootstrap/29382 * configure.in: Don't use -fkeep-inline-functions for GCC 3.3.1. * configure: Rebuilt. Modified: trunk/ChangeLog trunk/configure trunk/configure.ac -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #9 from jakub at gcc dot gnu dot org 2007-05-30 13:48 --- Subject: Bug 29382 Author: jakub Date: Wed May 30 13:48:07 2007 New Revision: 125184 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=125184 Log: PR bootstrap/29382 * configure.in: Don't use -fkeep-inline-functions for GCC 3.3.1. * configure: Rebuilt. Modified: branches/gcc-4_2-branch/ChangeLog branches/gcc-4_2-branch/configure branches/gcc-4_2-branch/configure.in -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #10 from jakub at gcc dot gnu dot org 2007-05-30 14:03 --- Worked around in 4.2.1+ and on the trunk. -- jakub at gcc dot gnu dot org changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #4 from jakub at gcc dot gnu dot org 2007-05-29 10:40 ---
When using gcc-3.2.3 as bootstrap compiler, i386.c is miscompiled
with -O0 -fkeep-inline-functions (the latter option is what is new
in gcc 4.2 and why 4.1.x bootstrap didn't suffer from this, see
2006-07-04 Eric Botcazou [EMAIL PROTECTED]
PR bootstrap/18058
* configure.in: Add -fkeep-inline-functions to CFLAGS for stage 1
if the bootstrap compiler is a GCC version that supports it.
* configure: Regenerate.
).
typedef struct rtx_def *rtx;
enum machine_mode
{
VOIDmode = 0,
DImode = 13
};
extern rtx gen_rtx_CONST_INT (enum machine_mode, long);
extern rtx gen_x86_shld_1 (rtx, rtx, rtx);
static __inline__ rtx
gen_x86_64_shld(rtx a, rtx b, rtx c)
{
return 0;
}
extern rtx emit_insn (rtx);
void
foo (rtx *high, rtx *low, enum machine_mode mode, int count)
{
emit_insn ((mode == DImode ? gen_x86_shld_1 : gen_x86_64_shld)
(high[0], low[0], gen_rtx_CONST_INT (VOIDmode, count)));
}
(extracted from i386.i) is miscompiled (tested latest RHEL3 gcc-3.2.3 as well
as current branches/gcc-3_2-branch), it calls gen_x86_64_shld unconditionally.
Removing -fkeep-inline-functions (or adding asm volatile () into the inline
function or making gen_x86_64_shld extern instead of static inline cures this).
Now, gcc-3_2-branch is long time closed, so IMNSHO gcc-4.2+ should work around
this bug.
--
jakub at gcc dot gnu dot org changed:
What|Removed |Added
CC||jakub at gcc dot gnu dot org
Status|RESOLVED|UNCONFIRMED
Resolution|WORKSFORME |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #5 from ebotcazou at gcc dot gnu dot org 2007-05-29 10:47 --- Now, gcc-3_2-branch is long time closed, so IMNSHO gcc-4.2+ should work around this bug. Agreed, we can simply say that GCC 3.2.x is not is a GCC version that supports it. Would you mind writing the patch? I don't have GCC 3.2.x handy. TIA. -- ebotcazou at gcc dot gnu dot org changed: What|Removed |Added CC||ebotcazou at gcc dot gnu dot ||org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #6 from jakub at gcc dot gnu dot org 2007-05-29 11:42 ---
Seems there were 2 separate bugs that are causing this miscompilation.
1) common_type (in contemporary gcc's common_pointer_type) will for the type
of the whole conditional expression use pointer to attribute const function
rather than non-const:
int fn1 (void);
int fn2 (void) __attribute__((const));
...
(cond ? fn1 : fn2)
I'd say that's an unfortunate effect from representing __attribute__((const))
as TREE_READONLY on the FUNCTION_TYPE rather than as an attribute. Say for
cond expr where one ptr target is volatile and the other is not the result
needs to be ptr to volatile and similarly for say
int *ptr1;
const int *ptr2;
cond ? ptr1 : ptr2
where the result should be pointer to const, a conservative choice. But for
__attribute__((const)) functions the conservative choise is the exact opposite,
if I have (cond ? fn1 : fn2) one of the functions isn't const and therefore
nothing should assume the whole thing is pointer to __attribute__((const))
function. gcc trunk handles this the same way.
2) because of 1), but also e.g. on
typedef struct rtx_def *rtx;
enum machine_mode
{
VOIDmode = 0,
DImode = 13
};
extern rtx gen_rtx_CONST_INT (enum machine_mode, long);
extern rtx gen_x86_shld_1 (rtx, rtx, rtx) __attribute__((const));
extern rtx gen_x86_64_shld (rtx, rtx, rtx) __attribute__((const));
extern rtx emit_insn (rtx);
void
foo (rtx *high, rtx *low, enum machine_mode mode, int count)
{
emit_insn ((mode == DImode ? gen_x86_shld_1 : gen_x86_64_shld)
(high[0], low[0], gen_rtx_CONST_INT (VOIDmode, count)));
}
where 1) doesn't apply a properly emitted expanded COND_EXPR into rtl is
passed through emit_libcall_block which changes:
(insn 31 0 32 (set (reg:CCZ 17 flags)
(compare:CCZ (mem/f:SI (plus:DI (reg/f:DI 54 virtual-stack-vars)
(const_int -20 [0xffec])) [0 mode+0 S4 A32])
(const_int 13 [0xd]))) -1 (nil)
(nil))
(jump_insn 32 31 34 (set (pc)
(if_then_else (ne (reg:CCZ 17 flags)
(const_int 0 [0x0]))
(label_ref 37)
(pc))) -1 (nil)
(nil))
(insn 34 32 35 (set (reg:DI 63)
(symbol_ref:DI (gen_x86_shld_1))) -1 (nil)
(nil))
(jump_insn 35 34 36 (set (pc)
(label_ref 40)) -1 (nil)
(nil))
(barrier 36 35 37)
(code_label 37 36 39 2 [0 uses])
(insn 39 37 40 (set (reg:DI 63)
(symbol_ref:DI (gen_x86_64_shld))) -1 (nil)
(nil))
(code_label 40 39 42 3 [0 uses])
(insn 42 40 44 (set (reg:DI 1 rdx)
(reg:DI 60)) -1 (nil)
(nil))
(insn 44 42 46 (set (reg:DI 4 rsi)
(mem:DI (reg/f:DI 61) [0 S8 A64])) -1 (nil)
(nil))
(insn 46 44 47 (set (reg:DI 5 rdi)
(mem:DI (reg/f:DI 62) [0 S8 A64])) -1 (nil)
(nil))
(call_insn/u 47 46 0 (set (reg:DI 0 rax)
(call (mem:QI (reg:DI 63) [0 S1 A8])
(const_int 0 [0x0]))) -1 (nil)
(nil)
(expr_list (use (reg:DI 5 rdi))
(expr_list (use (reg:DI 4 rsi))
(expr_list (use (reg:DI 1 rdx))
(nil)
into
(insn 34 30 39 (set (reg:DI 63)
(symbol_ref:DI (gen_x86_shld_1))) -1 (nil)
(nil))
(insn 39 34 31 (set (reg:DI 63)
(symbol_ref:DI (gen_x86_64_shld))) -1 (nil)
(nil))
(insn 31 39 32 (set (reg:CCZ 17 flags)
(compare:CCZ (mem/f:SI (plus:DI (reg/f:DI 54 virtual-stack-vars)
(const_int -20 [0xffec])) [0 mode+0 S4 A32])
(const_int 13 [0xd]))) -1 (nil)
(nil))
(jump_insn 32 31 35 (set (pc)
(if_then_else (ne (reg:CCZ 17 flags)
(const_int 0 [0x0]))
(label_ref 37)
(pc))) -1 (nil)
(nil))
(jump_insn 35 32 36 (set (pc)
(label_ref 40)) -1 (nil)
(nil))
(insn 34 30 39 (set (reg:DI 63)
(symbol_ref:DI (gen_x86_shld_1))) -1 (nil)
(nil))
(insn 39 34 31 (set (reg:DI 63)
(symbol_ref:DI (gen_x86_64_shld))) -1 (nil)
(nil))
(insn 31 39 32 (set (reg:CCZ 17 flags)
(compare:CCZ (mem/f:SI (plus:DI (reg/f:DI 54 virtual-stack-vars)
(const_int -20 [0xffec])) [0 mode+0 S4 A32])
(const_int 13 [0xd]))) -1 (nil)
(nil))
(jump_insn 32 31 35 (set (pc)
(if_then_else (ne (reg:CCZ 17 flags)
(const_int 0 [0x0]))
(label_ref 37)
(pc))) -1 (nil)
(nil))
(jump_insn 35 32 36 (set (pc)
(label_ref 40)) -1 (nil)
(nil))
(barrier 36 35 37)
(code_label 37 36 40 2 [0 uses])
(code_label 40 37 42 3 [0 uses])
(insn 42 40 44 (set (reg:DI 1 rdx)
(reg:DI 60)) -1 (nil)
(nil))
(insn 44 42 46 (set (reg:DI 4 rsi)
(mem:DI (reg/f:DI 61) [0 S8 A64])) -1 (nil)
(nil))
(insn 46 44 47 (set (reg:DI 5 rdi)
(mem:DI (reg/f:DI 62) [0 S8 A64])) -1 (nil)
(nil))
(call_insn/u 47 46 49 (set (reg:DI 0 rax)
(call (mem:QI (reg:DI 63) [0 S1 A8])
(const_int 0 [0x0]))) -1 (nil)
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #7 from jakub at gcc dot gnu dot org 2007-05-29 12:48 --- 2) is apparently PR11557, fixed in GCC 3.3.1+. So, I'd say as workaround we should not use -fkeep-inline-functions for GCC 3.3.1. Testing a patch for that. -- jakub at gcc dot gnu dot org changed: What|Removed |Added AssignedTo|unassigned at gcc dot gnu |jakub at gcc dot gnu dot org |dot org | Status|UNCONFIRMED |ASSIGNED Ever Confirmed|0 |1 Last reconfirmed|-00-00 00:00:00 |2007-05-29 12:48:39 date|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #3 from tru at pasteur dot fr 2007-05-21 15:43 --- [EMAIL PROTECTED] ~]$ gcc -v Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/3.2.3/specs Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --host=i386-redhat-linux Thread model: posix gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-58) [EMAIL PROTECTED] ~]$ rpm -q gcc gcc-3.2.3-58.i386 is failing too, but a plain gcc-3.4.6 can bootstrap gcc-4.2.0 -- tru at pasteur dot fr changed: What|Removed |Added CC||tru at pasteur dot fr http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #2 from pinskia at gcc dot gnu dot org 2007-03-05 19:43 --- No feedback in 3 months so closing. -- pinskia at gcc dot gnu dot org changed: What|Removed |Added Status|WAITING |RESOLVED Resolution||WORKSFORME http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
[Bug bootstrap/29382] Bootstrap comparison failure!
--- Comment #1 from pinskia at gcc dot gnu dot org 2006-10-07 20:07 --- This works for me on i686-linux-gnu. Can you first try compiling 3.4.x and then trying compiling the mainline with that? -- pinskia at gcc dot gnu dot org changed: What|Removed |Added Status|UNCONFIRMED |WAITING http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29382
