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| author | Alan Modra <amodra@gmail.com> | 2020-09-28 16:23:01 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2020-10-01 10:34:48 +0930 |
| commit | c6be439b37702f6ac4c2fc447c6f3ed1042b80a3 (patch) | |
| tree | 5f9cec57d320243058ebfe2b6b5e13b51555743c | |
| parent | cf7dae01734eea0dfb4c387e4cd40e1f9a682f56 (diff) | |
| download | gcc-c6be439b37702f6ac4c2fc447c6f3ed1042b80a3.zip gcc-c6be439b37702f6ac4c2fc447c6f3ed1042b80a3.tar.gz gcc-c6be439b37702f6ac4c2fc447c6f3ed1042b80a3.tar.bz2 | |
[RS6000] -mno-minimal-toc vs. power10 pcrelative
We've had this hack in the libgcc config to build libgcc with
-mcmodel=small for powerpc64 for a long time. It wouldn't be a bad
thing if someone who knows the multilib machinery well could arrange
for -mcmodel=small to be passed just for ppc64 when building for
earlier than power10. But for now, make -mno-minimal-toc do nothing
when pcrel. Which will do the right thing for any project that has
copied libgcc's trick.
We want this if configuring using --with-cpu=power10 to build a
power10 pcrel libgcc. --mcmodel=small turns off pcrel.
gcc/
* config/rs6000/linux64.h (SUBSUBTARGET_OVERRIDE_OPTIONS): Don't
set -mcmodel=small for -mno-minimal-toc when pcrel.
libgcc/
* config/rs6000/t-linux: Document purpose of -mno-minimal-toc.
| -rw-r--r-- | gcc/config/rs6000/linux64.h | 17 | ||||
| -rw-r--r-- | libgcc/config/rs6000/t-linux | 7 |
2 files changed, 19 insertions, 5 deletions
diff --git a/gcc/config/rs6000/linux64.h b/gcc/config/rs6000/linux64.h index 2ded330..5c9f8e3 100644 --- a/gcc/config/rs6000/linux64.h +++ b/gcc/config/rs6000/linux64.h @@ -132,20 +132,29 @@ extern int dot_symbols; if ((rs6000_isa_flags & OPTION_MASK_POWERPC64) == 0) \ { \ rs6000_isa_flags |= OPTION_MASK_POWERPC64; \ - error ("%<-m64%> requires a PowerPC64 cpu"); \ + error ("%<-m64%> requires a PowerPC64 cpu"); \ } \ + if (!global_options_set.x_rs6000_current_cmodel) \ + SET_CMODEL (CMODEL_MEDIUM); \ if ((rs6000_isa_flags_explicit \ & OPTION_MASK_MINIMAL_TOC) != 0) \ { \ if (global_options_set.x_rs6000_current_cmodel \ && rs6000_current_cmodel != CMODEL_SMALL) \ error ("%<-mcmodel incompatible with other toc options%>"); \ - SET_CMODEL (CMODEL_SMALL); \ + if (TARGET_MINIMAL_TOC) \ + SET_CMODEL (CMODEL_SMALL); \ + else if (TARGET_PCREL \ + || (PCREL_SUPPORTED_BY_OS \ + && (rs6000_isa_flags_explicit \ + & OPTION_MASK_PCREL) == 0)) \ + /* Ignore -mno-minimal-toc. */ \ + ; \ + else \ + SET_CMODEL (CMODEL_SMALL); \ } \ else \ { \ - if (!global_options_set.x_rs6000_current_cmodel) \ - SET_CMODEL (CMODEL_MEDIUM); \ if (rs6000_current_cmodel != CMODEL_SMALL) \ { \ if (!global_options_set.x_TARGET_NO_FP_IN_TOC) \ diff --git a/libgcc/config/rs6000/t-linux b/libgcc/config/rs6000/t-linux index 4f6d4c4..ed82194 100644 --- a/libgcc/config/rs6000/t-linux +++ b/libgcc/config/rs6000/t-linux @@ -1,3 +1,8 @@ SHLIB_MAPFILES += $(srcdir)/config/rs6000/libgcc-glibc.ver -HOST_LIBGCC2_CFLAGS += -mlong-double-128 -mno-minimal-toc +HOST_LIBGCC2_CFLAGS += -mlong-double-128 + +# This is a way of selecting -mcmodel=small for ppc64, which gives +# smaller and faster libgcc code. Directly specifying -mcmodel=small +# would need to take into account targets for which -mcmodel is invalid. +HOST_LIBGCC2_CFLAGS += -mno-minimal-toc |