These transformations obviously won't work for indexed (pre/post-inc) loads and
stores. In practice, I'm not sure there is any benefit to enabling them for
indexed nodes because other transformations that these might enable likely also
won't handle indexed nodes.
I don't have an in-tree test case that hits this problem, but an upcoming bug
fix will make it much more likely.
llvm-svn: 200023
This pass identifies expensive constants to hoist and coalesces them to
better prepare it for SelectionDAG-based code generation. This works around the
limitations of the basic-block-at-a-time approach.
First it scans all instructions for integer constants and calculates its
cost. If the constant can be folded into the instruction (the cost is
TCC_Free) or the cost is just a simple operation (TCC_BASIC), then we don't
consider it expensive and leave it alone. This is the default behavior and
the default implementation of getIntImmCost will always return TCC_Free.
If the cost is more than TCC_BASIC, then the integer constant can't be folded
into the instruction and it might be beneficial to hoist the constant.
Similar constants are coalesced to reduce register pressure and
materialization code.
When a constant is hoisted, it is also hidden behind a bitcast to force it to
be live-out of the basic block. Otherwise the constant would be just
duplicated and each basic block would have its own copy in the SelectionDAG.
The SelectionDAG recognizes such constants as opaque and doesn't perform
certain transformations on them, which would create a new expensive constant.
This optimization is only applied to integer constants in instructions and
simple (this means not nested) constant cast experessions. For example:
%0 = load i64* inttoptr (i64 big_constant to i64*)
Reviewed by Eric
llvm-svn: 200022
This enables IO error reports in both the child and server processes.
The scheme still isn't entirely satisfactory and output is jumbled but it beats
having no output at all. This will hopefully unblock ARM support (PR18057).
llvm-svn: 200017
There is no inline asm in a .s file. Therefore, there should be no logic to
handle it in the streamer. Inline asm only exists in bitcode files, so the
logic can live in the (long misnamed) AsmPrinter class.
llvm-svn: 200011
compile unit. Make these relocations on the platforms that need
relocations and add a routine to ensure that we don't put the
addresses in an offset table for split dwarf.
llvm-svn: 199990
This commit teaches the X86 backend to create the same X86 instructions when it
lowers an sadd/ssub with overflow intrinsic and a conditional branch that uses
that overflow result. This allows SelectionDAG to recognize and remove one of
the redundant operations.
This fixes <rdar://problem/15874016> and <rdar://problem/15661073>.
Reviewed by Nadav
llvm-svn: 199976
We completely skipped promotion in LICM if the loop has a preheader or
dedicated exits, but not *both*. We hoist if there is a preheader, and
sink if there are dedicated exits, but either hoisting or sinking can
move loop invariant code out of the loop!
I have no idea if this has a practical consequence. If anyone has ideas
for a test case, let me know.
llvm-svn: 199966
scale factors in memory addresses. As it does for .att_syntax.
It was producing:
Assertion failed: (((Scale == 1 || Scale == 2 || Scale == 4 || Scale == 8)) && "Invalid scale!"), function CreateMem, file /Volumes/SandBox/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp, line 1133.
rdar://14967214
llvm-svn: 199942
Eliminates the LLI_BUILDING_CHILD build hack from r199885.
Also add a FIXME to remove code that tricks the tests into passing when the
feature fails to work. Please don't do stuff like this, the tests exist for a
reason!
llvm-svn: 199929
Originally, BLX was passed as operand #0 in MachineInstr and as operand
#2 in MCInst. But now, it's operand #2 in both cases.
This patch also removes unnecessary FileCheck in the test case added by r199127.
llvm-svn: 199928
This patch adds the target analysis passes (usually TargetTransformInfo) to the
codgen pipeline. We also expose now the AddAnalysisPasses method through the C
API, because the optimizer passes would also benefit from better target-specific
cost models.
Reviewed by Andrew Kaylor
llvm-svn: 199926
Clang says that "flow" is unused when building LLD. This patch suppresses it.
Differential Revision: http://llvm-reviews.chandlerc.com/D2573
llvm-svn: 199922
