ignore alignment requirements for SIMD memory operands. This
is useful on architectures like the AMD 10h that do not trap on
unaligned references if a status bit is twiddled at startup time.
llvm-svn: 93151
be non-optimal. To be precise, we should avoid folding loads if the instructions
only update part of the destination register, and the non-updated part is not
needed. e.g. cvtss2sd, sqrtss. Unfolding the load from these instructions breaks
the partial register dependency and it can improve performance. e.g.
movss (%rdi), %xmm0
cvtss2sd %xmm0, %xmm0
instead of
cvtss2sd (%rdi), %xmm0
An alternative method to break dependency is to clear the register first. e.g.
xorps %xmm0, %xmm0
cvtss2sd (%rdi), %xmm0
llvm-svn: 91672
- This is an initial step towards -march=native support in Clang, and towards
eliminating host dependencies in the targets. See PR5389.
- Patch by Roman Divacky!
llvm-svn: 88768
Module*.
Also, dropped uses of TargetMachine where unnecessary. The only target which
still takes a TargetMachine& is Mips, I would appreciate it if someone would
normalize this to match other targets.
llvm-svn: 77918
- added processors k8-sse3, opteron-sse3, athlon64-sse3, amdfam10, and
barcelona with appropriate sse3/4a levels
- added FeatureSSE4A for amdfam10 processors
in X86Subtarget:
- added hasSSE4A
- updated AutoDetectSubtargetFeatures to detect SSE4A
- updated GetCurrentX86CPU to detect family 15 with sse3 as k8-sse3 and
family 10h as amdfam10
New processor names match those used by gcc.
Patch by Paul Redmond!
llvm-svn: 72434
and extern_weak_odr. These are the same as the non-odr versions,
except that they indicate that the global will only be overridden
by an *equivalent* global. In C, a function with weak linkage can
be overridden by a function which behaves completely differently.
This means that IP passes have to skip weak functions, since any
deductions made from the function definition might be wrong, since
the definition could be replaced by something completely different
at link time. This is not allowed in C++, thanks to the ODR
(One-Definition-Rule): if a function is replaced by another at
link-time, then the new function must be the same as the original
function. If a language knows that a function or other global can
only be overridden by an equivalent global, it can give it the
weak_odr linkage type, and the optimizers will understand that it
is alright to make deductions based on the function body. The
code generators on the other hand map weak and weak_odr linkage
to the same thing.
llvm-svn: 66339
is given, override the subtarget settings and enable 64-bit support.
This restores the earlier behavior, and fixes regressions on
Non-64-bit-capable x86-32 hosts.
This isn't necessarily the best approach, but the most obvious
alternative is to require -mcpu=x86-64 or -mattr=+64bit to be used
with -march=x86-64 when the host doesn't have 64-bit support. This
makes things little more consistent, but it's less convenient, and
it has the practical drawback of requiring lots of test changes, so
I opted for the above approach for now.
llvm-svn: 63642
SSE2, however it's possible to disable SSE2, and the subtarget support
code thinks that if 64-bit implies SSE2 and SSE2 is disabled then
64-bit should also be disabled. Instead, just mark all the 64-bit
subtargets as explicitly supporting SSE2.
Also, move the code that makes -march=x86-64 enable 64-bit support by
default to only apply when there is no explicit subtarget. If you
need to specify a subtarget and you want 64-bit code, you'll need to
select a subtarget that supports 64-bit code.
llvm-svn: 63575
David Greene