[Bug c/19102] New: -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[Bug c/19102] New: -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[bero at arklinux dot org]

gcc -Wp,-MD,init/.main.o.d -nostdinc -iwithprefix include -D__KERNEL__ 
-Iinclude  -Wall -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing 
-fno-common -ffreestanding -std=gnu89 -O2     -fomit-frame-pointer -pipe 
-msoft-float -mpreferred-stack-boundary=2 -march=pentium3 
-Iinclude/asm-i386/mach-default -Wdeclaration-after-statement    
-DKBUILD_BASENAME=main -DKBUILD_MODNAME=main -c -o init/.tmp_main.o 
init/main.c 
init/main.c: In function `unknown_bootoption': 
include/asm/string.h:190: error: `asm' operand requires impossible reload 
include/asm/string.h:190: error: `asm' operand requires impossible reload 
include/asm/string.h:129: error: `asm' operand requires impossible reload 
init/main.c:197: error: insn does not satisfy its constraints: 
(insn 611 481 200 5 (set (reg:SI 1 dx) 
        (reg/v/f:SI 22 xmm1 [orig:89 s ] [89])) 36 {*movsi_1} (nil) 
    (nil)) 
init/main.c:197: confused by earlier errors, bailing out 
make[1]: *** [init/main.o] Error 1 
make: *** [init] Error 2 
 
 
Works with any of -march=i386, -march=i586, -march=i686, -march=pentium4, 
-march=athlon

-- 
           Summary: -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-
                    branch as of 2004/12/20
           Product: gcc
           Version: 3.4.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bero at arklinux dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-ark-linux
  GCC host triplet: i686-ark-linux
GCC target triplet: i686-ark-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug c/19102] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[bero at arklinux dot org]

------- Additional Comments From bero at arklinux dot org  2004-12-21 10:18 -------
Created an attachment (id=7789)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=7789&action=view)
Preprocessed source


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug c/19102] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[bero at arklinux dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |3.4.4
      Known to work|                            |3.4.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[belyshev at lubercy dot com]

------- Additional Comments From belyshev at lubercy dot com  2004-12-21 12:22 -------
/* reduced testcase, use "-O1 -march=pentium3" */

int unknown_bootoption (void)
{
  int i, j, k, l;
  for (i = 0; i < 2; i++)
      asm volatile(""
                   :"=a" (j), "=&S" (k), "=&c" (l)
                   :"1" (0), "2" (0));
  return 0;
}


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rth at gcc dot gnu dot org
           Severity|normal                      |critical
             Status|UNCONFIRMED                 |NEW
          Component|c                           |target
     Ever Confirmed|                            |1
  GCC build triplet|i686-ark-linux              |
   GCC host triplet|i686-ark-linux              |
 GCC target triplet|i686-ark-linux              |i686-*-*
           Keywords|                            |ice-on-valid-code
   Last reconfirmed|0000-00-00 00:00:00         |2004-12-21 12:22:41
               date|                            |
            Summary|-march=pentium3 breaks linux|[3.4 Regression] -
                   |kernel compiles w/ gcc-3_4- |march=pentium3 breaks linux
                   |branch as of 2004/12/20     |kernel compiles w/ gcc-3_4-
                   |                            |branch as of 2004/12/20
   Target Milestone|---                         |3.4.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-12-21 16:44 -------
Hmm, it worked with 2004-12-11.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[bero at arklinux dot org]

------- Additional Comments From bero at arklinux dot org  2004-12-21 17:55 -------
Worked in 2004-12-17 too, broken in 2004-12-20 and 2004-12-21 (I don't have 
-18 and -19) 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[bero at arklinux dot org]

------- Additional Comments From bero at arklinux dot org  2004-12-21 18:00 -------
Must be a cc1 issue - 2004-12-21 with 
2004-12-17's /usr/libexec/gcc/*/3.4.4/cc1 works 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[ebotcazou at gcc dot gnu dot org]

------- Additional Comments From ebotcazou at gcc dot gnu dot org  2004-12-22 11:27 -------
Introduced with:

2004-12-19  Richard Henderson  <rth@redhat.com>

	* config/i386/i386.c (ix86_hard_regno_mode_ok): Always accept all SSE,
	MMX, 3DNOW modes in SSE registers; always accept all MMX, 3DNOW modes
	in MMX registers.
	* config/i386/i386.h (VALID_SSE2_REG_MODE): Don't include
	VALID_MMX_REG_MODE.
	* config/i386/i386.md (movv4sf_internal, movv4si_internal, 
	movv2di_internal, movv2si_internal, movv4hi_internal,
	movv2sf_internal, movv2df_internal, movv8hi_internal,
	movv16qi_internal, movti_internal): Add leading '*' to name.
	(movv2di_internal, movv2df_internal, movv8hi_internal,
	movv16qi_internal, movv2df, movv8hi, movv16qi, movv2di,
	pushv2di, pushv8hi, pushv16qi): Enable for SSE1.
	(movv2si_internal, movv4hi_internal): Add SSE alternatives.
	(movv8qi_internal, movv2sf_internal): Likewise.
	(movtf): Simplify conditional.
	(movv2sf, pushv2sf): Enable for MMX.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2004-12-21 12:22:41         |2004-12-22 11:27:44
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[ebotcazou at gcc dot gnu dot org]

------- Additional Comments From ebotcazou at gcc dot gnu dot org  2004-12-22 11:43 -------
Investigating.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |ebotcazou at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[ebotcazou at gcc dot gnu dot org]

------- Additional Comments From ebotcazou at gcc dot gnu dot org  2004-12-22 12:24 -------
Why do we allow MMX modes in SSE regs now?  The following patchlet is sufficient
to fix the problem:

Index: config/i386/i386.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/i386/i386.c,v
retrieving revision 1.635.2.18
diff -u -p -r1.635.2.18 i386.c
--- config/i386/i386.c  20 Dec 2004 05:37:36 -0000      1.635.2.18
+++ config/i386/i386.c  22 Dec 2004 12:21:42 -0000
@@ -14931,9 +14931,7 @@ ix86_hard_regno_mode_ok (int regno, enum
          out of SSE registers, even when no operation instructions
          are available.  */
       return (VALID_SSE_REG_MODE (mode)
-             || VALID_SSE2_REG_MODE (mode)
-             || VALID_MMX_REG_MODE (mode)
-             || VALID_MMX_REG_MODE_3DNOW (mode));
+             || VALID_SSE2_REG_MODE (mode));
     }
   if (MMX_REGNO_P (regno))
     {


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[ebotcazou at gcc dot gnu dot org]

------- Additional Comments From ebotcazou at gcc dot gnu dot org  2004-12-22 18:49 -------
I can't do much more at this point.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu dot
                   |                            |org
         AssignedTo|ebotcazou at gcc dot gnu dot|unassigned at gcc dot gnu
                   |org                         |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[rth at gcc dot gnu dot org]

------- Additional Comments From rth at gcc dot gnu dot org  2004-12-22 19:12 -------
Subject: Re:  [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

> Why do we allow MMX modes in SSE regs now?

Because x86-64 calling conventions demand it.


r~


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[rth at gcc dot gnu dot org]

------- Additional Comments From rth at gcc dot gnu dot org  2004-12-22 20:02 -------
And, actually, we allowed MMX modes with -msse2 before, so there must be another 
explanation of why things wouldn't have been failing with -march=pentium4.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |rth at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[ebotcazou at gcc dot gnu dot org]

------- Additional Comments From ebotcazou at gcc dot gnu dot org  2004-12-22 20:24 -------
> > Why do we allow MMX modes in SSE regs now?
> 
> Because x86-64 calling conventions demand it.

The calling conventions for vector types I presume?  The problem is that SImode
slipped through the cracks so the register allocator now jumps from SIREG to
INT_SSE_REGS for SImode pseudos.  Is that an unintended side-effect?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[ebotcazou at gcc dot gnu dot org]

------- Additional Comments From ebotcazou at gcc dot gnu dot org  2004-12-22 23:18 -------
> And, actually, we allowed MMX modes with -msse2 before, so there must be another 
> explanation of why things wouldn't have been failing with -march=pentium4.

Allocation ordering considerations?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[rth at gcc dot gnu dot org]

------- Additional Comments From rth at gcc dot gnu dot org  2004-12-22 23:27 -------
Apparently register move costs.

Testing a Large Hack to prevent this suddenly appearing on the 3.4 branch.

For mainline, move pattern constraints should be fixed, and folks will have
to make sure to use -mno-sse when sse is not desired.  Plus, -mno-sse will
have to be fixed such that it's effective when -march implies sse[23], and
we'll have to add extra code to not ICE on x86-64 when the ABI specifies
that parameters go in disabled registers.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[ak at muc dot de]

------- Additional Comments From ak at muc dot de  2004-12-22 23:53 -------
FWIW i compiled a full 3.3-hammer compiled 2.6.10rc3 x86-64 kernel
for suspicious use of %xmm or %mm and there wasn't any.

There also is a warning in all 2.6 x86-64 kernels for kernel FPU use at runtime.

So at least on x86-64 it doesn't seem to be a real issue in practice.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-12-23 01:31 -------
Subject: Bug 19102

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_4-branch
Changes by:	rth@gcc.gnu.org	2004-12-23 01:31:20

Modified files:
	gcc            : ChangeLog 
	gcc/config/i386: i386.c 

Log message:
	PR target/19102
	* config/i386/i386.c (x86_inter_unit_moves): Disable.
	(ix86_hard_regno_mode_ok): Disallow SSE2 and MMX scalar modes
	in SSE registers when only SSE1 enabled.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=2.2326.2.750&r2=2.2326.2.751
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/config/i386/i386.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.635.2.18&r2=1.635.2.19



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102

[Bug target/19102] [3.4 Regression] -march=pentium3 breaks linux kernel compiles w/ gcc-3_4-branch as of 2004/12/20

[rth at gcc dot gnu dot org]

------- Additional Comments From rth at gcc dot gnu dot org  2004-12-23 01:40 -------
http://gcc.gnu.org/ml/gcc-patches/2004-12/msg01777.html

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19102