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 `{{.*}} `.
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
This change adds support for the following MIPS target triples:
mipsisa32r6-linux-gnu
mipsisa32r6el-linux-gnu
mipsisa64r6-linux-gnuabi64
mipsisa64r6el-linux-gnuabi64
mipsisa64r6-linux-gnuabin32
mipsisa64r6el-linux-gnuabin32
Patch by Yun Qiang Su.
Differential revision: https://reviews.llvm.org/D50850
llvm-svn: 344608
The `GNUABIN32` environment in a target triple implies using the N32
ABI. This patch adds support for this environment and switches on N32
ABI if necessary.
Patch by Patch by YunQiang Su.
Differential revision: https://reviews.llvm.org/D51464
llvm-svn: 344570
Summary:
Before this change, we only emit the XRay attributes in LLVM IR when the
-fxray-instrument flag is provided. This may cause issues with thinlto
when the final binary is being built/linked with -fxray-instrument, and
the constitutent LLVM IR gets re-lowered with xray instrumentation.
With this change, we can honour the "never-instrument "attributes
provided in the source code and preserve those in the IR. This way, even
in thinlto builds, we retain the attributes which say whether functions
should never be XRay instrumented.
This change addresses llvm.org/PR38922.
Reviewers: mboerger, eizan
Subscribers: mehdi_amini, dexonsmith, cfe-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D52015
llvm-svn: 342200
Summary: I'm not sure why they were in different files, but it's kind of harder to maintain. I create this patch partially for initiate a discussion.
Reviewers: dberris
Subscribers: nemanjai, cfe-commits
Differential Revision: https://reviews.llvm.org/D30118
llvm-svn: 295778
-fxray-instrument: enables XRay annotation of IR
-fxray-instruction-threshold: configures the threshold for function size (looking at IR instructions), and allow LLVM to decide whether to add the nop sleds later on in the process.
Also implements the related xray_always_instrument and xray_never_instrument function attributes.
Patch by Dean Michael Berris.
llvm-svn: 275330
Fangrui Song