This should be covered by PR110308 (proposed fix attached there) and PR110313. Our bootstrap runs are still in progress to confirm.
On Thu, 22 Jun 2023 at 09:40, Richard Biener <richard.guent...@gmail.com> wrote: > > On Thu, Jun 22, 2023 at 1:42 AM Thiago Jung Bauermann > <thiago.bauerm...@linaro.org> wrote: > > > > > > Hello, > > > > Jeff Law <jeffreya...@gmail.com> writes: > > > > > On 6/19/23 22:52, Tamar Christina wrote: > > > > > >>> It's a bit hackish, but could we reject the stack pointer for operand1 > > >>> in the > > >>> stack-tie? And if we do so, does it help? > > >> Yeah this one I had to defer until later this week to look at closer > > >> because what I'm > > >> wondering about is whether the optimization should apply to frame related > > >> RTX as well. > > >> Looking at the description of RTX_FRAME_RELATED_P that this optimization > > >> may > > >> end up de-optimizing RISC targets by creating an offset that is larger > > >> than offset > > >> which can be used from a SP making reload having to spill. i.e. > > >> sometimes the > > >> move was explicitly done. So perhaps it should not apply it to > > >> RTX_FRAME_RELATED_P in find_oldest_value_reg and > > >> copyprop_hardreg_forward_1? > > >> Other parts of this pass already seems to bail out in similar > > >> situations. So I needed > > >> to > > >> write some testcases to check what would happen in these cases hence the > > >> deferral. > > >> to later in the week. > > > Rejecting for RTX_FRAME_RELATED_P would seem reasonable and probably > > > better in general to > > > me. The cases where we're looking to clean things up aren't really in the > > > prologue/epilogue, but instead in the main body after register > > > elimination has turned fp > > > into sp + offset, thus making all kinds of things no longer valid. > > > > The problems I reported were fixed by commits: > > > > 580b74a79146 "aarch64: Robustify stack tie handling" > > 079f31c55318 "aarch64: Fix gcc.target/aarch64/sve/pcs failures" > > > > Thanks! > > > > But unfortunately I'm still seeing bootstrap failures (ICE segmentation > > fault) in today's trunk with build config bootstrap-lto in both > > armv8l-linux-gnueabihf and aarch64-linux-gnu. > > If there's not yet a bugreport for this please make sure to open one so > this issue doesn't get lost. > > > If I revert commit 6a2e8dcbbd4b "cprop_hardreg: Enable propagation of > > the stack pointer if possible" from trunk then both bootstraps succeed. > > > > Here's the command I'm using to build on armv8l: > > > > ~/src/configure \ > > SHELL=/bin/bash \ > > --with-gnu-as \ > > --with-gnu-ld \ > > --disable-libmudflap \ > > --enable-lto \ > > --enable-shared \ > > --without-included-gettext \ > > --enable-nls \ > > --with-system-zlib \ > > --disable-sjlj-exceptions \ > > --enable-gnu-unique-object \ > > --enable-linker-build-id \ > > --disable-libstdcxx-pch \ > > --enable-c99 \ > > --enable-clocale=gnu \ > > --enable-libstdcxx-debug \ > > --enable-long-long \ > > --with-cloog=no \ > > --with-ppl=no \ > > --with-isl=no \ > > --disable-multilib \ > > --with-float=hard \ > > --with-fpu=neon-fp-armv8 \ > > --with-mode=thumb \ > > --with-arch=armv8-a \ > > --enable-threads=posix \ > > --enable-multiarch \ > > --enable-libstdcxx-time=yes \ > > --enable-gnu-indirect-function \ > > --disable-werror \ > > --enable-checking=yes \ > > --enable-bootstrap \ > > --with-build-config=bootstrap-lto \ > > --enable-languages=c,c++,fortran,lto \ > > && make \ > > profiledbootstrap \ > > SHELL=/bin/bash \ > > -w \ > > -j 40 \ > > CFLAGS_FOR_BUILD="-pipe -g -O2" \ > > CXXFLAGS_FOR_BUILD="-pipe -g -O2" \ > > LDFLAGS_FOR_BUILD="-static-libgcc" \ > > MAKEINFOFLAGS=--force \ > > BUILD_INFO="" \ > > MAKEINFO=echo > > > > And here's the slightly different one for aarch64-linux: > > > > ~/src/configure \ > > SHELL=/bin/bash \ > > --with-gnu-as \ > > --with-gnu-ld \ > > --disable-libmudflap \ > > --enable-lto \ > > --enable-shared \ > > --without-included-gettext \ > > --enable-nls \ > > --with-system-zlib \ > > --disable-sjlj-exceptions \ > > --enable-gnu-unique-object \ > > --enable-linker-build-id \ > > --disable-libstdcxx-pch \ > > --enable-c99 \ > > --enable-clocale=gnu \ > > --enable-libstdcxx-debug \ > > --enable-long-long \ > > --with-cloog=no \ > > --with-ppl=no \ > > --with-isl=no \ > > --disable-multilib \ > > --enable-fix-cortex-a53-835769 \ > > --enable-fix-cortex-a53-843419 \ > > --with-arch=armv8-a \ > > --enable-threads=posix \ > > --enable-multiarch \ > > --enable-libstdcxx-time=yes \ > > --enable-gnu-indirect-function \ > > --disable-werror \ > > --enable-checking=yes \ > > --enable-bootstrap \ > > --with-build-config=bootstrap-lto \ > > --enable-languages=c,c++,fortran,lto \ > > && make \ > > profiledbootstrap \ > > SHELL=/bin/bash \ > > -w \ > > -j 40 \ > > LDFLAGS_FOR_TARGET="-Wl,-fix-cortex-a53-843419" \ > > CFLAGS_FOR_BUILD="-pipe -g -O2" \ > > CXXFLAGS_FOR_BUILD="-pipe -g -O2" \ > > LDFLAGS_FOR_BUILD="-static-libgcc" \ > > MAKEINFOFLAGS=--force \ > > BUILD_INFO="" \ > > MAKEINFO=echo > > > > -- > > Thiago
