[CodeGen] Introduce a FAULTING_LOAD_OP pseudo-op.
Summary:
This instruction encodes a loading operation that may fault, and a label
to branch to if the load page-faults. The locations of potentially
faulting loads and their "handler" destinations are recorded in a
FaultMap section, meant to be consumed by LLVM's clients.
Nothing generates FAULTING_LOAD_OP instructions yet, but they will be
used in a future change.
The documentation (FaultMaps.rst) needs improvement and I will update
this diff with a more expanded version shortly.
Depends on D10196
Reviewers: rnk, reames, AndyAyers, ab, atrick, pgavlin
Reviewed By: atrick, pgavlin
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10197
llvm-svn: 239740
diff --git a/llvm/lib/MC/MCObjectFileInfo.cpp b/llvm/lib/MC/MCObjectFileInfo.cpp
index 83a08e2..3ef87b5 100644
--- a/llvm/lib/MC/MCObjectFileInfo.cpp
+++ b/llvm/lib/MC/MCObjectFileInfo.cpp
@@ -238,6 +238,9 @@
StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
0, SectionKind::getMetadata());
+ FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
+ 0, SectionKind::getMetadata());
+
TLSExtraDataSection = TLSTLVSection;
}
@@ -518,6 +521,9 @@
StackMapSection =
Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
+
+ FaultMapSection =
+ Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
}
void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) {