is general goodness because it allows ORs to be converted to LEA to avoid
inserting copies. However, this is bad because it makes the generated .s
file less obvious and gives valgrind heartburn (tons of false positives in
bitfield code).
While the general fix should be in valgrind, we can at least try to avoid
emitting ADD instructions that *don't* get promoted to LEA. This is more
work because it requires introducing pseudo instructions to represents
"add that knows the bits are disjoint", but hey, people really love valgrind.
This fixes this testcase:
https://bugs.kde.org/show_bug.cgi?id=242137#c20
the add r/i cases are coming next.
llvm-svn: 116007
The x86_mmx type is used for MMX intrinsics, parameters and
return values where these use MMX registers, and is also
supported in load, store, and bitcast.
Only the above operations generate MMX instructions, and optimizations
do not operate on or produce MMX intrinsics.
MMX-sized vectors <2 x i32> etc. are lowered to XMM or split into
smaller pieces. Optimizations may occur on these forms and the
result casted back to x86_mmx, provided the result feeds into a
previous existing x86_mmx operation.
The point of all this is prevent optimizations from introducing
MMX operations, which is unsafe due to the EMMS problem.
llvm-svn: 115243
- Do not clobber al during variadic calls, this is AMD64 ABI-only feature
- Emit wincall64, where necessary
Patch by Cameron Esfahani!
llvm-svn: 111289
term goal here is to be able to match enough of vector_shuffle and build_vector
so all avx intrinsics which aren't mapped to their own built-ins but to
shufflevector calls can be codegen'd. This is the first (baby) step, support
building zeroed vectors.
llvm-svn: 110897
asmprinter or mangler around. This is option #B for killing off
X86InstrInfo::GetInstSizeInBytes. Option #A (killing
"needsexactsize") was sent for consideration to llvmdev.
llvm-svn: 109056
of AsmPrinter and InstLowering into libx86 and out of the
asmprinter subdirectory. Now X86/AsmPrinter just depends on
MC stuff, not all of codegen and LLVM IR.
llvm-svn: 108782
Chris Lattner