[Bug rtl-optimization/111384] missed optimization: GCC adds extra any extend when storing subreg#0 multiple times

2023-10-31 Thread lis8215 at gmail dot com via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111384

Siarhei Volkau  changed:

   What|Removed |Added

 Resolution|--- |DUPLICATE
 Status|NEW |RESOLVED

--- Comment #5 from Siarhei Volkau  ---
Dup of bug 104387.

*** This bug has been marked as a duplicate of bug 104387 ***

[Bug rtl-optimization/111384] missed optimization: GCC adds extra any extend when storing subreg#0 multiple times

2023-10-07 Thread law at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111384

Jeffrey A. Law  changed:

   What|Removed |Added

   Last reconfirmed||2023-10-07
 Ever confirmed|0   |1
 Status|UNCONFIRMED |NEW

--- Comment #4 from Jeffrey A. Law  ---
So this is something we've been pondering over in rv64 land.  Joern has an
extension to DCE which tracks subobjects in an attempt to determine if bits set
by sign/zero extensions are never read.  If they aren't read, then the
extension can be eliminated.

[Bug rtl-optimization/111384] missed optimization: GCC adds extra any extend when storing subreg#0 multiple times

2023-09-12 Thread pinskia at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111384

--- Comment #3 from Andrew Pinski  ---
I thought I saw/reported a similar bug but I can't find it right now.

[Bug rtl-optimization/111384] missed optimization: GCC adds extra any extend when storing subreg#0 multiple times

2023-09-12 Thread pinskia at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111384

Andrew Pinski  changed:

   What|Removed |Added

   Severity|normal  |enhancement

[Bug rtl-optimization/111384] missed optimization: GCC adds extra any extend when storing subreg#0 multiple times

2023-09-12 Thread lis8215 at gmail dot com via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111384

--- Comment #2 from Siarhei Volkau  ---
Well what the godbolt says with -O2 -fomit-frame-pointer.

ARM:
uxthr0, r0  @ << zero extend
strhr0, [r1]
strhr0, [r2]
bx  lr

ARM64:
and w0, w0, 65535   @ << zero extend
strhw0, [x1]
strhw0, [x2]
ret

MIPS64:
andi$4,$4,0x@ << zero extend
sh  $4,0($5)
jr  $31
sh  $4,0($6)

MRISC32:
shufr1, r1, #2888   @ << zero extend
sth r1, [r2]
sth r1, [r3]
ret

RISC-V:
sllia0,a0,16@ << zero extend
srlia0,a0,16@ << zero extend
sh  a0,0(a1)
sh  a0,0(a2)
ret

RISC-V (64-bit):
sllia0,a0,48@ << zero extend
srlia0,a0,48@ << zero extend
sh  a0,0(a1)
sh  a0,0(a2)
ret

Xtensa ESP32:
entry   sp, 32
extui   a2, a2, 0, 16   @ << zero extend
s16ia2, a3, 0
s16ia2, a4, 0
retw.n

Loongarch64:
bstrpick.w  $r4,$r4,15,0  @ << zero extend
st.h$r4,$r5,0
st.h$r4,$r6,0
jr  $r1

MIPS:
andi$4,$4,0x@ << zero extend
sh  $4,0($5)
jr  $31
sh  $4,0($6)

SH:
extu.w  r4,r4   @ << zero extend
mov.w   r4,@r5
rts 
mov.w   r4,@r6


Other available at godbolt (x86-64/Power/Power64/s390) unaffected.

[Bug rtl-optimization/111384] missed optimization: GCC adds extra any extend when storing subreg#0 multiple times

2023-09-12 Thread rguenth at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111384

Richard Biener  changed:

   What|Removed |Added

Version|unknown |14.0
  Component|middle-end  |rtl-optimization

--- Comment #1 from Richard Biener  ---
can you name one of many?