Add the commandline options -fprofile-instr-generate[=filename] and -profile-instr-use=filename
-fprofile-instr-generate
-- Add instrumentation on branches, switches, and function entry; uses LLVM's InstrProf pass.
-- Link to profile runtime that writes instrumentation counters to a file.
-fprofile-instr-use
-- Read profile data from a file and apply branch weights to branches and switches, and annotate functions with entrycount in LLVM IR.
-- Functions with low or high entrycount are marked with 'cold' or 'inlinehint'.
The only statement type without PGO yet is "try-finally".
A new pragma, `pragma(LDC_profile_instr, [ true | false ])`, is added to selectively disable/enable instrumentation of functions (granularity = whole functions).
The runtime library ldc-profile-rt is a copy of LLVM compiler-rt lib/profile. It has to be exactly in-sync with the LLVM version, and thus we need a copy for each PGO-supported LLVM (>=3.7).
import ldc.profile for a D interface to ldc-profile-rt (for example to reset execution counts after a program startup phase).
The instrumentation data is mainly passed on to LLVM: function-entry counts and branch counts/probabilities. LDC marks functions as hot when "execution count is 30% of the maximum function execution count", and marks functions as cold if their count is 1% of maximum function execution count.
The source of LLVM's llvm-profdata tool is hereby included in LDCs repository (different source for each LLVM version), and the binary is included in the install bin folder.
The executable is named "ldc-profdata" to avoid clashing with llvm-profdata on the same machine. This is needed because profdata executable has to be in-sync with the LLVM version used to build LDC.
Maintenance burden: for trunk LLVM, we have to keep ldc-profile-rt and llvm-profdata in sync. There is no diff with upstream; but because of active development there are the occasional API changes.
Allow ABIRewrites to return the D parameter's LL value directly.
Most rewrites store to memory anyway, so let the D parameter point
directly to that memory instead of a dedicated alloca bitcopy.
When certain attributes are applied to the calling function, like "unsafe-fp-math", the inlined inlineIR function has to have the same attributes otherwise the calling function attribute will be reset to the safe merge of the two: "false". Because the same inlineIR function can be called in different functions using an alias definition, a new function (with possibly different attributes) has to be instantiated upon every call.
Related GH issue #1438
The first check is what DMD also does; the second one is to replace
the assertion by an ICE, since the bug can apparently be triggered
rather reliably.
See GitHub #1360.
This is required to resolve the type for AAPCS/AAPCS64.
Up to now it was not necessary because only char* was used.
AAPCS/AAPCS64 use a special extern(C++) struct __va_list.
Also adds the CMake infrastructure to compile and link the D source files.
The build is partially broken:
- A few files in Phobos and druntime do not build
- MSVC build is broken because of unresolved symbols involving reals
And for sret args too, except for MSVC targets.
At least on Win64, the sret align attributes lead to ICEs for std.bitmanip
and std.uni (release only), when computing the known alignment in the LLVM
inliner pass:
Assertion failed: I->getParent()->getParent() ==
Q.CxtI->getParent()->getParent() && "Got assumption for the wrong function!",
file C:\LDC\llvm\lib\Analysis\ValueTracking.cpp, line 711
Trying to get the alignment right by using the first non-default one
in the following order of descending priority:
VarDeclaration::alignment [variables only of course]
Type::alignment()
Type::alignsize()
This fixes `align(x) struct S { ... }`.
