For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.
To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.
To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
We currently emit incorrect codegen for this constraint because we set it as a
constraint that allows registers. This will cause the value to be copied to the
stack and that address to be passed as the address. This is not what we want.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=42762
Differential revision: https://reviews.llvm.org/D77542
Summary:
Clang -fpic defaults to -fno-semantic-interposition (GCC -fpic defaults
to -fsemantic-interposition).
Users need to specify -fsemantic-interposition to get semantic
interposition behavior.
Semantic interposition is currently a best-effort feature. There may
still be some cases where it is not handled well.
Reviewers: peter.smith, rnk, serge-sans-paille, sfertile, jfb, jdoerfert
Subscribers: dschuff, jyknight, dylanmckay, nemanjai, jvesely, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, arphaman, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73865
Summary:
"ww" and "ws" are both constraint codes for VSX vector registers that
hold scalar double data. "ww" is preferred for float while "ws" is
preferred for double.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D64119
llvm-svn: 365106
This adds support for the PPC "wc" inline asm constraint (used for allocating
individual CR bits). Support for this constraint type was recently added to the
LLVM PowerPC backend. Although gcc does not currently support allocating
individual CR bits, this identifier choice has been coordinated with the gcc
PowerPC team, and will be marked as reserved for this purpose in the gcc
constraints.md file.
Prior to this change, none of the multi-character PPC constraints were handled
correctly (the '^' escape character was not being added as required by the
parsing code in LLVM). This should now be fixed. I'll add tests for these other
constraints as support is added for them in the backend.
llvm-svn: 202658
Fangrui Song