| Message ID | m339h8w48s.fsf@richards-thinkpad.stglab.manchester.uk.ibm.com |
|---|---|
| State | New |
| Headers | show |
On 11/08/11 12:56, Richard Sandiford wrote: > Trying to compile a certain embedded benchmark with -falign-loops=8 > or above fails due to out-of-range references to the literal pool. > This is because arm_reorg doesn't take label alignment into account. > > Fixed with the patch below. Tested on arm-linux-gnueabi. I also > tried compiling libav with and without the patch (not using -falign-loops > for either run). As hoped, there were no changes in assembly output. > OK to install? > > Richard > > > gcc/ > * config/arm/arm.c (get_label_padding): New function. > (create_fix_barrier, md_reorg): Likewise. > OK. R.
On Thu, Aug 11, 2011 at 1:56 PM, Richard Sandiford <rdsandiford@googlemail.com> wrote: > gcc/ > * config/arm/arm.c (get_label_padding): New function. > (create_fix_barrier, md_reorg): Likewise. The ChangeLog doesn't match the patch: * create_fix_barrier is not a new function. * md_reorg should be arm_reorg Ciao! Steven > Index: gcc/config/arm/arm.c > =================================================================== > --- gcc/config/arm/arm.c 2011-08-11 11:49:18.780977049 +0100 > +++ gcc/config/arm/arm.c 2011-08-11 12:14:42.074629364 +0100 > @@ -11719,6 +11719,19 @@ get_jump_table_size (rtx insn) > return 0; > } > > +/* Return the maximum amount of padding that will be inserted before > + label LABEL. */ > + > +static HOST_WIDE_INT > +get_label_padding (rtx label) > +{ > + HOST_WIDE_INT align, min_insn_size; > + > + align = 1 << label_to_alignment (label); > + min_insn_size = TARGET_THUMB ? 2 : 4; > + return align > min_insn_size ? align - min_insn_size : 0; > +} > + > /* Move a minipool fix MP from its current location to before MAX_MP. > If MAX_MP is NULL, then MP doesn't need moving, but the addressing > constraints may need updating. */ > @@ -12265,8 +12278,12 @@ create_fix_barrier (Mfix *fix, HOST_WIDE > within range. */ > gcc_assert (GET_CODE (from) != BARRIER); > > - /* Count the length of this insn. */ > - count += get_attr_length (from); > + /* Count the length of this insn. This must stay in sync with the > + code that pushes minipool fixes. */ > + if (LABEL_P (from)) > + count += get_label_padding (from); > + else > + count += get_attr_length (from); > > /* If there is a jump table, add its length. */ > tmp = is_jump_table (from); > @@ -12696,6 +12713,11 @@ arm_reorg (void) > insn = table; > } > } > + else if (LABEL_P (insn)) > + /* Add the worst-case padding due to alignment. We don't add > + the _current_ padding because the minipool insertions > + themselves might change it. */ > + address += get_label_padding (insn); > } > > fix = minipool_fix_head; >
Steven Bosscher <stevenb.gcc@gmail.com> writes: > On Thu, Aug 11, 2011 at 1:56 PM, Richard Sandiford > <rdsandiford@googlemail.com> wrote: > >> gcc/ >> * config/arm/arm.c (get_label_padding): New function. >> (create_fix_barrier, md_reorg): Likewise. > > The ChangeLog doesn't match the patch: > * create_fix_barrier is not a new function. > * md_reorg should be arm_reorg Sorry, now fixed. Richard
Index: gcc/config/arm/arm.c =================================================================== --- gcc/config/arm/arm.c 2011-08-11 11:49:18.780977049 +0100 +++ gcc/config/arm/arm.c 2011-08-11 12:14:42.074629364 +0100 @@ -11719,6 +11719,19 @@ get_jump_table_size (rtx insn) return 0; } +/* Return the maximum amount of padding that will be inserted before + label LABEL. */ + +static HOST_WIDE_INT +get_label_padding (rtx label) +{ + HOST_WIDE_INT align, min_insn_size; + + align = 1 << label_to_alignment (label); + min_insn_size = TARGET_THUMB ? 2 : 4; + return align > min_insn_size ? align - min_insn_size : 0; +} + /* Move a minipool fix MP from its current location to before MAX_MP. If MAX_MP is NULL, then MP doesn't need moving, but the addressing constraints may need updating. */ @@ -12265,8 +12278,12 @@ create_fix_barrier (Mfix *fix, HOST_WIDE within range. */ gcc_assert (GET_CODE (from) != BARRIER); - /* Count the length of this insn. */ - count += get_attr_length (from); + /* Count the length of this insn. This must stay in sync with the + code that pushes minipool fixes. */ + if (LABEL_P (from)) + count += get_label_padding (from); + else + count += get_attr_length (from); /* If there is a jump table, add its length. */ tmp = is_jump_table (from); @@ -12696,6 +12713,11 @@ arm_reorg (void) insn = table; } } + else if (LABEL_P (insn)) + /* Add the worst-case padding due to alignment. We don't add + the _current_ padding because the minipool insertions + themselves might change it. */ + address += get_label_padding (insn); } fix = minipool_fix_head;