This is the first incremental patch to implement this feature. It adds no
functionality to LLVM but setup up the information needed from targets in
order to implement the optimization correctly. Each target needs to specify
the maximum number of store operations for conversion of the llvm.memset,
llvm.memcpy, and llvm.memmove intrinsics into a sequence of store operations.
The limit needs to be chosen at the threshold of performance for such an
optimization (generally smallish). The target also needs to specify whether
the target can support unaligned stores for multi-byte store operations.
This helps ensure the optimization doesn't generate code that will trap on
an alignment errors.
More patches to follow.
llvm-svn: 22468
vector that represents the .o file at once, build up a vector for each
section of the .o file. This is needed because the .o file writer needs
to be able to switch between sections as it emits them (e.g. switch
between the .text section and the .rel section when emitting code).
This patch has no functionality change.
llvm-svn: 22453
legalizer to eliminate them. With this comes the expected code quality
improvements, such as, for this:
double foo(unsigned short X) { return X; }
we now generate this:
_foo:
subl $4, %esp
movzwl 8(%esp), %eax
movl %eax, (%esp)
fildl (%esp)
addl $4, %esp
ret
instead of this:
_foo:
subl $4, %esp
movw 8(%esp), %ax
movzwl %ax, %eax ;; Load not folded into this.
movl %eax, (%esp)
fildl (%esp)
addl $4, %esp
ret
-Chris
llvm-svn: 22449
SelectionDAGLegalize::ExpandLegalUINT_TO_FP method.
Add a new method, PromoteLegalUINT_TO_FP, which allows targets to request
that UINT_TO_FP operations be promoted to a larger input type. This is
useful for targets that have some UINT_TO_FP or SINT_TO_FP operations but
not all of them (like X86).
The same should be done with SINT_TO_FP, but this patch does not do that
yet.
llvm-svn: 22447
Add parenthesis around the value being negated; that way, if the value
begins with a minus sign (e.g. negative integer), we won't generate a
C predecrement operator by mistake.
llvm-svn: 22437
It is not safe to call LegalizeOp on something that has already been legalized.
Instead, just force another iteration of legalization.
This could affect all platforms but X86, as this codepath is dynamically
dead on X86 (ISD::MEMSET and friends are legal).
llvm-svn: 22419
This patch completes the changes for making lli thread-safe. Here's the list
of changes:
* The Support/ThreadSupport* files were removed and replaced with the
MutexGuard.h file since all ThreadSupport* declared was a Mutex Guard.
The implementation of MutexGuard.h is now based on sys::Mutex which hides
its implementation and makes it unnecessary to have the -NoSupport.h and
-PThreads.h versions of ThreadSupport.
* All places in ExecutionEngine that previously referred to "Mutex" now
refer to sys::Mutex
* All places in ExecutionEngine that previously referred to "MutexLocker"
now refer to MutexGuard (this is frivolous but I believe the technically
correct name for such a class is "Guard" not a "Locker").
These changes passed all of llvm-test. All we need now are some test cases
that actually use multiple threads.
llvm-svn: 22404
Add a Mutex class for thread synchronization in a platform-independent way.
The current implementation only supports pthreads. Win32 use of Critical
Sections will be added later. The design permits other threading models to
be used if (and only if) pthreads is not available.
llvm-svn: 22403
