Commit Graph

1163 Commits

Author SHA1 Message Date
David Greene
71847813bc Have asm printers use formatted_raw_ostream directly to avoid a
dynamic_cast<>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75670 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-14 20:18:05 +00:00
Torok Edwin
c23197a26f llvm_unreachable->llvm_unreachable(0), LLVM_UNREACHABLE->llvm_unreachable.
This adds location info for all llvm_unreachable calls (which is a macro now) in
!NDEBUG builds.
In NDEBUG builds location info and the message is off (it only prints
"UREACHABLE executed").


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75640 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-14 16:55:14 +00:00
Dan Gohman
2e4da5e4ab Delete a spurious const.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75493 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-13 20:46:11 +00:00
David Greene
014700c1a8 Add infrastructure to allow post instruction printing action triggers.
We'll eventually use this to print comments in asm files and do other
fun things.

This adds interfaces to the AsmPrinter and changes TableGen to invoke
the postInstructionAction when appropriate.  It also add parameters to
TargetAsmInfo to control comment layout.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75490 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-13 20:25:48 +00:00
Jakob Stoklund Olesen
ee787ff01a Add CCIfSRet calling convention predicate.
The blackfin calling convention uses a different register for sret arguments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75417 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-12 13:15:50 +00:00
Torok Edwin
c25e7581b9 assert(0) -> LLVM_UNREACHABLE.
Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75379 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-11 20:10:48 +00:00
Evan Cheng
261ce1d5f8 Remove TargetInstrInfo::CommuteChangesDestination and added findCommutedOpIndices which returns the operand indices which are swapped (when applicable). This allows for some code clean up and future enhancements.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75264 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-10 19:15:51 +00:00
Evan Cheng
bfa5cf144a 80 col violation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75226 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-10 05:20:19 +00:00
Evan Cheng
910139f9ca Targets sometimes assign fixed stack object to spill certain callee-saved
registers based on dynamic conditions. For example, X86 EBP/RBP, when used as
frame register has to be spilled in the first fixed object. It should inform
PEI this so it doesn't get allocated another stack object. Also, it should not
be spilled as other callee-saved registers but rather its spilling and restoring
are being handled by emitPrologue and emitEpilogue. Avoid spilling it twice.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75116 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-09 06:53:48 +00:00
Bruno Cardoso Lopes
ac57e6e498 Add the Object Code Emitter class. Original patch by Aaron Gray, I did some
cleanup, removed some #includes and moved Object Code Emitter out-of-line.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74813 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06 05:09:34 +00:00
Duncan Sands
98749f851d In this unreachable code, return an initialized value.
This stops gcc warning about possible uses of an uninitialized
value when compiling with assertions turned off.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74775 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-03 16:00:23 +00:00
Tilmann Scheller
ffd0200abf Implement the SVR4 ABI for PowerPC.
Implement LowerFORMAL_ARGUMENTS_SVR4().
Implement LowerCALL_SVR4().
Add support for split arguments.
Implement by value parameter passing for aggregates.
Add support for variable argument lists.
Create the spill area for argument registers of variable argument functions no longer at a fixed offset.
Make sure callee saved registers are spilled to the correct stack offsets.
Change allocation order of non-volatile floating-point registers.
Add VRSAVE to the list of callee-saved registers, add CallConvLowering for vararg calls.
Add support for variable argument calls with Vector arguments.
Add support for VR and VRSAVE save area, improve allocation order for non-volatile vector registers.
Stop creating illegal i8 values in LowerVASTART().
Add memory access width hints.
Make sure to reserve space on the stack for the frame pointer.
When using the SVR4 ABI, reserve r13 for the Small Data Area pointer.
Assure that the frame pointer is spilled to the correct location on the stack.
Some FP registers were not marked as volatile.
Make sure the i64 words from a long double are passed either both in registers or both on the stack.
Only put integer arguments in registers which are not marked with the inreg flag.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74765 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-03 06:45:56 +00:00
Tilmann Scheller
6b61cd185e Add NumFixedArgs attribute to CallSDNode which indicates the number of fixed arguments in a vararg call.
With the SVR4 ABI on PowerPC, vector arguments for vararg calls are passed differently depending on whether they are a fixed or a variable argument. Variable vector arguments always go into memory, fixed vector arguments are put 
into vector registers. If there are no free vector registers available, fixed vector arguments are put on the stack.

The NumFixedArgs attribute allows to decide for an argument in a vararg call whether it belongs to the fixed or variable portion of the parameter list.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74764 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-03 06:44:53 +00:00
Bruno Cardoso Lopes
3d62a412fb Remove getFunctionAlignment from TargetELFInfo and use new MachineFunction alignment method
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74686 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-02 02:13:13 +00:00
Bill Wendling
b4202b84d7 Update comments to make it clear that the function alignment is the Log2 of the
bytes and not bytes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74624 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-01 18:50:55 +00:00
Bill Wendling
20c568f366 Add an "alignment" field to the MachineFunction object. It makes more sense to
have the alignment be calculated up front, and have the back-ends obey whatever
alignment is decided upon.

This allows for future work that would allow for precise no-op placement and the
like.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74564 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-30 22:38:32 +00:00
David Greene
02a6218774 Increase limit for OpActions array
The OpActions array had a limit of 32 value types, so change it to use
MVT::MAX_ALLOWED_VALUETYPE in its declaration and change the accesses to
this array to work with a VT.getSimpleVT() that is larger than 32.

Also, add a comment to the place where MVT::MAX_ALLOWED_VALUETYPE is
defined indicating that it must be a multiple of 32.

This is part of the work allow MVT::LAST_VALUETYPE be greater than 32.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74130 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 22:22:02 +00:00
David Greene
f2e19d5dcf This increases the maximum for MVT::LAST_VALUETYPE
This change doubles the allowable value for MVT::LAST_VALUETYPE. It does
this by doing several things.

1. Introduces MVT::MAX_ALLOWED_LAST_VALUETYPE which in this change has a
value of 64.  This value contains the current maximum for the
MVT::LAST_VALUETYPE.

2. Instead of checking "MVT::LAST_VALUETYPE <= 32", all of those uses
now become "MVT::LAST_VALUETYPE <= MVT::MAX_ALLOWED_LAST_VALUETYPE"

3. Changes the dimension of the ValueTypeActions from 2 elements to four
elements and adds comments ahead of the declaration indicating the it is
"(MVT::MAX_ALLOWED_LAST_VALUETYPE/32) * 2".  This at least lets us find
what is affected if and when MVT::MAX_ALLOWED_LAST_VALUETYPE gets
changed.

4. Adds initializers for the new elements of ValueTypeActions.

This does NOT add any types in MVT. That would be done separately.

This doubles the size of ValueTypeActions from 64 bits to 128 bits and
gives us the freedom to add more types for AVX.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74110 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 19:41:55 +00:00
Bob Wilson
a96751fc8f Provide InitializeAllTargets and InitializeNativeTarget functions in the
C bindings.  Change all the backend "Initialize" functions to have C linkage.
Change the "llvm/Config/Targets.def" header to use C-style comments to avoid
compile warnings.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74026 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-23 23:59:40 +00:00
Douglas Gregor
bcba7f95c2 Work around build problem with OpenJDK, which defines X86 as a
macro. Fixes PR 4427. Patch by Xerxes Rånby!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73961 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-23 17:21:35 +00:00
Bruno Cardoso Lopes
0d3193ef3c Add more methods to gather target specific elf stuff
Support for .text relocations, implementing TargetELFWriter overloaded methods for x86/x86_64.
Use a map to track global values to their symbol table indexes
Code cleanup and small fixes



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73894 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 19:16:16 +00:00
Chris Lattner
c12430644a implement support for lowering subregs when preparing to print
LEA64_32r, eliminating a bunch of modifier logic stuff on addr modes.

Implement support for printing mbb labels as operands.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73817 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-20 07:03:18 +00:00
Devang Patel
1e86a66b00 mv CodeGen/DebugLoc.h Support/DebugLoc.h
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73786 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 22:08:58 +00:00
Chris Lattner
4e0f25b603 merge the common darwin settings from the X86/PPC/ARM targets
into DarwinTargetAsmInfo.cpp.  The remaining differences should
be evaluated.  It seems strange that x86/arm has .zerofill but ppc
doesn't, etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73742 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 00:08:39 +00:00
Chris Lattner
a93ca92379 move mangler quote handling from asm printers to TargetAsmInfo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73738 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 23:41:35 +00:00
Chris Lattner
b839c3f577 simplify macro debug info directive handling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73736 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 23:31:37 +00:00
Evan Cheng
f9f1da17f8 - Update register allocation hint after coalescing. This is done by the target since the hint is target dependent. This is important for ARM register pair hints.
- Register allocator should resolve the second part of the hint (register number) before passing it to the target since it knows virtual register to physical register mapping.
- More fixes to get ARM load / store double word working.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73671 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 02:04:01 +00:00
Chris Lattner
5f1a5c7f57 Add a utility header that makes it easy to link in the right set
of targets for various purposes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73610 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-17 16:42:01 +00:00
Anton Korobeynikov
0d492bdf4d Address more comments :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73430 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-15 22:08:48 +00:00
Anton Korobeynikov
52edfc7a6d Document ABIType enum. Patch by Sandeep Patel!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73427 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-15 21:46:02 +00:00
Evan Cheng
358dec5180 Part 1.
- Change register allocation hint to a pair of unsigned integers. The hint type is zero (which means prefer the register specified as second part of the pair) or entirely target dependent.
- Allow targets to specify alternative register allocation orders based on allocation hint.

Part 2.
- Use the register allocation hint system to implement more aggressive load / store multiple formation.
- Aggressively form LDRD / STRD. These are formed *before* register allocation. It has to be done this way to shorten live interval of base and offset registers. e.g.
v1025 = LDR v1024, 0
v1026 = LDR v1024, 0
=>
v1025,v1026 = LDRD v1024, 0

If this transformation isn't done before allocation, v1024 will overlap v1025 which means it more difficult to allocate a register pair.

- Even with the register allocation hint, it may not be possible to get the desired allocation. In that case, the post-allocation load / store multiple pass must fix the ldrd / strd instructions. They can either become ldm / stm instructions or back to a pair of ldr / str instructions.

This is work in progress, not yet enabled.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73381 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-15 08:28:29 +00:00
Evan Cheng
90f95f88c6 Move register allocation preference (or hint) from LiveInterval to MachineRegisterInfo. This allows more passes to set them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73346 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 20:22:55 +00:00
Bruno Cardoso Lopes
ae9163f0e2 Introduce new BinaryObject (blob) class, ELF Writer modified to use it. BinaryObject.h by Aaron Gray
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73333 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 07:53:21 +00:00
Bruno Cardoso Lopes
d00d4159d4 Use forward declarations and move TargetELFWriterInfo impl to a new file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73209 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-11 22:13:00 +00:00
Bruno Cardoso Lopes
c997d45ae5 Support for ELF Visibility
Emission for globals, using the correct data sections
Function alignment can be computed for each target using TargetELFWriterInfo
Some small fixes



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73201 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-11 19:16:03 +00:00
David Greene
f5aefbdb79 Change IndexedModeAction representation.
This changes the IndexedModeAction representation to remove the
limitation on the number of value types in MVT.  This limitation
prevents us from specifying AVX types.

Prior to this change IndexedModActions was represented as follows...

uint64_t IndexedModeActions[2][ISD::LAST_INDEXED_MODE];

the first dimension was used to represent loads, then stores.  This
imposed a limitation of 32 on the number of value types that could be
handled with this method.  The value type was used to shift the two bits
into and out of the approprate bits in the uint64_t.

With this change the array is now represented as ...

uint8_t IndexedModeActions[MVT::LAST_VALUETYPE][2][ISD::LAST_INDEXED_MODE];

Takes more space but removes the limitation on MVT::LAST_VALUETYPE.  The
first dimension is now the value_type for the reference.  The second
dimension is the load [0] vs. store[1].  The third dimension represents
the various modes for load store.  Accesses are now direct, no shifting
or masking.

There are other limitations that need to be removed, so that
MVT::LAST_VALUETYPE can be greater than 32.  This is merely the first
step towards that goal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73104 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-09 00:19:10 +00:00
David Greene
63ec51d86b Oops, didn't mean to commit 73102 yet. Revert it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73103 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-08 23:54:42 +00:00
David Greene
9df4eb8cfe Change IndexedModeAction representation.
This changes the IndexedModeAction representation to remove the
limitation on the number of value types in MVT.  This limitation
prevents us from specifying AVX types.

Prior to this change IndexedModActions was represented as follows...

uint64_t IndexedModeActions[2][ISD::LAST_INDEXED_MODE];

the first dimension was used to represent loads, then stores.  This
imposed a limitation of 32 on the number of value types that could be
handled with this method.  The value type was used to shift the two bits
into and out of the approprate bits in the uint64_t.

With this change the array is now represented as ...

uint8_t IndexedModeActions[MVT::LAST_VALUETYPE][2][ISD::LAST_INDEXED_MODE];

Takes more space but removes the limitation on MVT::LAST_VALUETYPE.  The
first dimension is now the value_type for the reference.  The second
dimension is the load [0] vs. store[1].  The third dimension represents
the various modes for load store.  Accesses are now direct, no shifting
or masking.

There are other limitations that need to be removed, so that
MVT::LAST_VALUETYPE can be greater than 32.  This is merely the first
step towards that goal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73102 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-08 23:53:19 +00:00
Anton Korobeynikov
0eebf653a7 The attached patches implement most of the ARM AAPCS-VFP hard float
ABI. The missing piece is support for putting "homogeneous aggregates"
into registers.

Patch by Sandeep Patel!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73095 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-08 22:53:56 +00:00
David Greene
e1b469170b Make IntInits and ListInits typed. This helps deduce types of !if and
other operators.  For the rare cases where a list type cannot be
deduced, provide a []<type> syntax, where <type> is the list element
type.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73078 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-08 20:23:18 +00:00
Bruno Cardoso Lopes
f5b0c5a1c7 Remove elf specific info from ELFWriter.h to Elf.h. Code cleanup and more comments added
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72982 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-06 03:56:29 +00:00
Devang Patel
578efa920a Add new function attribute - noimplicitfloat
Update code generator to use this attribute and remove NoImplicitFloat target option.
Update llc to set this attribute when -no-implicit-float command line option is used.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72959 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-05 21:57:13 +00:00
Nate Begeman
abc0199680 Adapt the x86 build_vector dagcombine to the current state of the legalizer.
build vectors with i64 elements will only appear on 32b x86 before legalize.
Since vector widening occurs during legalize, and produces i64 build_vector 
elements, the dag combiner is never run on these before legalize splits them
into 32b elements.

Teach the build_vector dag combine in x86 back end to recognize consecutive 
loads producing the low part of the vector.

Convert the two uses of TLI's consecutive load recognizer to pass LoadSDNodes
since that was required implicitly.

Add a testcase for the transform.

Old:
	subl	$28, %esp
	movl	32(%esp), %eax
	movl	4(%eax), %ecx
	movl	%ecx, 4(%esp)
	movl	(%eax), %eax
	movl	%eax, (%esp)
	movaps	(%esp), %xmm0
	pmovzxwd	%xmm0, %xmm0
	movl	36(%esp), %eax
	movaps	%xmm0, (%eax)
	addl	$28, %esp
	ret

New:
	movl	4(%esp), %eax
	pmovzxwd	(%eax), %xmm0
	movl	8(%esp), %eax
	movaps	%xmm0, (%eax)
	ret




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72957 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-05 21:37:30 +00:00
Devang Patel
d18e31ae17 Add new function attribute - noredzone.
Update code generator to use this attribute and remove DisableRedZone target option.
Update llc to set this attribute when -disable-red-zone command line option is used.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72894 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-04 22:05:33 +00:00
Dale Johannesen
874ae251c3 Revert 72707 and 72709, for the moment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72712 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-02 03:12:52 +00:00
Dale Johannesen
4150d83abe Make the implicit inputs and outputs of target-independent
ADDC/ADDE use MVT::i1 (later, whatever it gets legalized to)
instead of MVT::Flag.  Remove CARRY_FALSE in favor of 0; adjust
all target-independent code to use this format.

Most targets will still produce a Flag-setting target-dependent
version when selection is done.  X86 is converted to use i32
instead, which means TableGen needs to produce different code
in xxxGenDAGISel.inc.  This keys off the new supportsHasI1 bit
in xxxInstrInfo, currently set only for X86; in principle this
is temporary and should go away when all other targets have
been converted.  All relevant X86 instruction patterns are
modified to represent setting and using EFLAGS explicitly.  The
same can be done on other targets.

The immediate behavior change is that an ADC/ADD pair are no
longer tightly coupled in the X86 scheduler; they can be
separated by instructions that don't clobber the flags (MOV).
I will soon add some peephole optimizations based on using
other instructions that set the flags to feed into ADC.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72707 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-01 23:27:20 +00:00
Bruno Cardoso Lopes
a3f99f9033 First patch in the direction of splitting MachineCodeEmitter in two subclasses:
JITCodeEmitter and ObjectCodeEmitter. No functional changes yet. Patch by Aaron Gray



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72631 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-30 20:51:52 +00:00
Bill Wendling
4d4eab219a Untabify.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72603 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-30 00:58:37 +00:00
Evan Cheng
abdbc57abb Default isNarrowingProfitable to false.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72561 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-29 05:31:40 +00:00
Evan Cheng
8b944d39b3 Added optimization that narrow load / op / store and the 'op' is a bit twiddling instruction and its second operand is an immediate. If bits that are touched by 'op' can be done with a narrower instruction, reduce the width of the load and store as well. This happens a lot with bitfield manipulation code.
e.g.
orl     $65536, 8(%rax)
=>
orb     $1, 10(%rax)

Since narrowing is not always a win, e.g. i32 -> i16 is a loss on x86, dag combiner consults with the target before performing the optimization.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72507 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-28 00:35:15 +00:00