[Bug rtl-optimization/33927] New: replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[Bug rtl-optimization/33927] New: replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[pinskia at gcc dot gnu dot org]

Like PR 33790, dse.c could handle the case mentioned in there.  The current
issue is that it does:
  if (GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))
    return false;

And the clases are different, one is the vector float class (V4SF) and the
other is the vector integer class (V4SI) (or just integer class [TI], spu). 

Testcase where an extra store/load exists:

#define vector __attribute__((__vector_size__(16) ))

typedef vector float vec_float4;
typedef struct {
        vec_float4 data;
} VecFloat4;

typedef struct {
        vec_float4 a;
        vec_float4 b;
} VecFloat4x2;


VecFloat4 test1(VecFloat4 a, VecFloat4 b)
{
        a.data = a.data+b.data;
        return a;
}


VecFloat4x2 test2(VecFloat4x2 data)
{
        data.a = data.a+data.a;
        data.b = data.b+data.b;
        return data;
}


-- 
           Summary: replace_read in dse.c could handle cases where
                    GET_MODE_CLASS (read_mode) != GET_MODE_CLASS
                    (store_mode) (and the size is the same)
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
GCC target triplet: spu-elf, powerpc64-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33927

[Bug rtl-optimization/33927] replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[rsandifo at gcc dot gnu dot org]

------- Comment #1 from rsandifo at gcc dot gnu dot org  2008-03-09 16:51 -------
This is one of the issues that I originally tried to fix for 4.3:

    http://gcc.gnu.org/ml/gcc-patches/2007-10/msg01661.html

but that was too invasive for stage 3.  I resubmitted it after 4.4 opened:

    http://gcc.gnu.org/ml/gcc-patches/2008-02/msg01227.html

and pinged it yesterday:

    http://gcc.gnu.org/ml/gcc-patches/2008-03/msg00537.html

I'll add the PR number to the change log.


-- 

rsandifo at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |rsandifo at gcc dot gnu dot
                   |dot org                     |org
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2008-
                   |                            |02/msg01227.html
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
           Keywords|                            |patch
   Last reconfirmed|0000-00-00 00:00:00         |2008-03-09 16:51:46
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33927

[Bug rtl-optimization/33927] replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[Kenneth dot Zadeck at NaturalBridge dot com]

------- Comment #2 from Kenneth dot Zadeck at NaturalBridge dot com  2008-03-10 01:48 -------
I tested the latest patch on ppc-32 and ppc-64 and there were no regressions.

i did have trouble applying the patch.  The second frag of the update for the
test case did not apply.


-- 

Kenneth dot Zadeck at NaturalBridge dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33927

[Bug rtl-optimization/33927] replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[rsandifo at gcc dot gnu dot org]

------- Comment #3 from rsandifo at gcc dot gnu dot org  2008-03-22 19:38 -------
Subject: Bug 33927

Author: rsandifo
Date: Sat Mar 22 19:37:53 2008
New Revision: 133452

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=133452
Log:
gcc/
        PR rtl-optimization/33927
        * Makefile.in (dse.o): Depend on $(TM_P_H).
        * expr.h (extract_low_bits): Declare.
        * expmed.c (extract_low_bits): New function.
        * rtlhooks.c (gen_lowpart_general): Generalize SUBREG handling.
        * dse.c: Include tm_p.h.
        (find_shift_sequence): Remove the read_reg argument and return the
        read value.  Emit the instructions instead of returning them.
        Iterate on new_mode rather than calculating it each time.
        Check MODES_TIEABLE_P.  Use simplify_gen_subreg to convert the
        source to NEW_MODE and extract_low_bits to convert the shifted
        value to READ_MODE.
        (replace_read): Allow the load and store to have different mode
        classes.  Use extract_low_bits when SHIFT == 0.  Create the shift
        or extraction instructions before trying the replacement.  Update
        dump-file code accordingly, avoiding use of REGNO (store_info->rhs).

gcc/testsuite/
        * gcc.target/mips/dse-1.c: Add checks for zeros.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/Makefile.in
    trunk/gcc/dse.c
    trunk/gcc/expmed.c
    trunk/gcc/expr.h
    trunk/gcc/rtlhooks.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.target/mips/dse-1.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33927

[Bug rtl-optimization/33927] replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[rsandifo at gcc dot gnu dot org]

-- 

rsandifo at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|rsandifo 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=33927

[Bug rtl-optimization/33927] replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[rsandifo at gcc dot gnu dot org]

------- Comment #4 from rsandifo at gcc dot gnu dot org  2008-03-22 19:45 -------
I've applied a patch that should fix this.  No-one's confirmed
whether it does though, so I'm marking the PR as waiting.


-- 

rsandifo at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33927

[Bug rtl-optimization/33927] replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2008-03-23 00:48 -------
(In reply to comment #4)
> I've applied a patch that should fix this.  No-one's confirmed
> whether it does though, so I'm marking the PR as waiting.

And I just confirmed, it does fix it, on powerpc64-darwin:

--- old.s       2008-03-22 17:47:53.000000000 -0700
+++ new.s       2008-03-22 17:47:18.000000000 -0700
@@ -24,22 +24,15 @@ _test2:
        stw r0,-4(r1)
        oris r0,r0,0xc000
        mtspr 256,r0
-       li r0,48
-       li r9,64
-       vaddfp v2,v2,v2
-       addi r2,r1,16
-       addi r11,r1,48
+       vaddfp v0,v2,v2
+       addi r2,r1,48
        lwz r12,-4(r1)
-       vaddfp v3,v3,v3
-       stvx v2,0,r11
-       stvx v3,r2,r0
-       lvx v0,0,r11
-       lvx v1,r2,r0
-       addi r2,r1,-128
-       stvx v0,r2,r0
-       stvx v1,r2,r9
-       lvx v2,r2,r0
-       lvx v3,r2,r9
+       vaddfp v1,v3,v3
+       vor v2,v0,v0
+       vor v3,v1,v1
+       stvx v0,0,r2
+       addi r2,r1,64
+       stvx v1,0,r2
        mtspr 256,r12
        blr
        .subsections_via_symbols

Thanks for the fix Richard.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33927

[Bug rtl-optimization/33927] replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[eres at il dot ibm dot com]

------- Comment #6 from eres at il dot ibm dot com  2008-03-23 07:20 -------
(In reply to comment #5)
> (In reply to comment #4)
> > I've applied a patch that should fix this.  No-one's confirmed
> > whether it does though, so I'm marking the PR as waiting.
> And I just confirmed, it does fix it, on powerpc64-darwin:

It also fixes the problem on spu-gcc, but on powerpc64-linux 
it seems that the problem still exists:

-----------------------------------
On spu-gcc:

 test2:
-       hbr     .L5,$lr
+       fa      $4,$4,$4
        stqd    $sp,-128($sp)
+       fa      $3,$3,$3
        ai      $sp,$sp,-128
-       stqd    $3,64($sp)
-       stqd    $4,80($sp)
-       lqd     $4,80($sp)
-       lqd     $5,64($sp)
-       fa      $3,$4,$4
-       fa      $2,$5,$5
-       stqd    $3,48($sp)
-       stqd    $2,32($sp)
-       lqd     $4,48($sp)
-       lqd     $3,32($sp)
        ai      $sp,$sp,128
-.L5:
        bi      $lr

-----------------------------------

On powerpc64-linux :

        .file   "struct1.c"
        .section        ".text"
        .align 2
        .p2align 4,,15
        .globl test1
        .type   test1, @function
test1:
        stwu 1,-32(1)
        mfvrsave 0
        stw 0,28(1)
        oris 0,0,0xc000
        mtvrsave 0
        lvx 0,0,4
        lvx 1,0,5
        vaddfp 0,0,1
        lwz 12,28(1)
        stvx 0,0,3
        mtvrsave 12
        addi 1,1,32
        blr
        .size   test1,.-test1
        .align 2
        .p2align 4,,15
        .globl test2
        .type   test2, @function
test2:
        stwu 1,-32(1)
        mfvrsave 0
        stw 0,28(1)
        oris 0,0,0xc000
        mtvrsave 0
        li 0,16
        lvx 1,0,4
        lvx 0,4,0
        vaddfp 1,1,1
        vaddfp 0,0,0
        lwz 12,28(1)
        stvx 1,0,4
        stvx 0,4,0
        stvx 0,3,0
        stvx 1,0,3
        mtvrsave 12
        addi 1,1,32
        blr
        .size   test2,.-test2
        .ident  "GCC: (GNU) 4.4.0 20080323 (experimental)"
        .section        .note.GNU-stack,"",@progbits


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33927

[Bug rtl-optimization/33927] replace_read in dse.c could handle cases where GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode) (and the size is the same)

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2008-03-23 17:49 -------
(In reply to comment #6)
> It also fixes the problem on spu-gcc, but on powerpc64-linux 
> it seems that the problem still exists:

No, the problem does not still exist, what exist is an extra store and that is
really recorded as PR 30271.

Thanks,
Andrew Pinski


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33927