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| author | Iain Sandoe <iain@sandoe.co.uk> | 2021-12-20 15:19:50 +0000 |
|---|---|---|
| committer | Iain Sandoe <iain@sandoe.co.uk> | 2021-12-24 10:47:05 +0000 |
| commit | 19bf83a9a068f2d5293b63c9300f99172b2d278d (patch) | |
| tree | 2413e5caabb730ef387a3dcbe758fff1ba0a35fb /gcc/config.gcc | |
| parent | 8381075ff3f5f5aefcd7027d7c5136a0e61e654a (diff) | |
| download | gcc-19bf83a9a068f2d5293b63c9300f99172b2d278d.zip gcc-19bf83a9a068f2d5293b63c9300f99172b2d278d.tar.gz gcc-19bf83a9a068f2d5293b63c9300f99172b2d278d.tar.bz2 | |
Darwin: Update rules for handling alignment of globals.
The current rule was too strict and has not been required since Darwin11.
This relaxes the constraint to allow up to 2^28 alignment for non-common
entities. Common is still restricted to a maximum aligment of 2^15.
When the host is an older version of Darwin ( earlier that 11 ) then the
existing constraint is still applied. Note that this is a host constraint
not a target one (so that a compilation on 10.7 targeting 10.6 is allowed
to use a greater alignment than the tools on 10.6 support). This matches
the behaviour of clang.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
gcc/ChangeLog:
* config.gcc: Emit L2_MAX_OFILE_ALIGNMENT with suitable
values for the host.
* config/darwin.c (darwin_emit_common): Error for alignment
values > 32768.
* config/darwin.h (MAX_OFILE_ALIGNMENT): Rework to use the
configured L2_MAX_OFILE_ALIGNMENT.
gcc/testsuite/ChangeLog:
* gcc.dg/darwin-aligned-globals.c: New test.
* gcc.dg/darwin-comm-1.c: New test.
* gcc.dg/attr-aligned.c: Amend for new alignment values on
Darwin.
* gcc.target/i386/pr89261.c: Likewise.
Diffstat (limited to 'gcc/config.gcc')
| -rw-r--r-- | gcc/config.gcc | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/gcc/config.gcc b/gcc/config.gcc index bf1c745..294f312 100644 --- a/gcc/config.gcc +++ b/gcc/config.gcc @@ -677,6 +677,20 @@ case ${target} in macos_min=0 fi def_ld64=85.2 + # Tools hosted on earlier versions of Darwin constrained all object + # alignment to be 2^15 or smaller. From Darwin11 (macOS 10.7) the + # alignment of non-common is allowed to be up to 2^28. Note that the + # larger alignment is permitted when targeting 10.6 from 10.7 so that + # the constraint only need be applied per host (and only if the host + # is Darwin). + case ${host} in + *-*-darwin[4-9]* | *-*-darwin10*) + tm_defines="$tm_defines L2_MAX_OFILE_ALIGNMENT=15U" + ;; + *) + tm_defines="$tm_defines L2_MAX_OFILE_ALIGNMENT=28U" + ;; + esac case ${target} in # Darwin 4 to 19 correspond to macOS 10.0 to 10.15 *-*-darwin[4-9]* | *-*-darwin1[0-9]*) |