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
DWARF requires frame moves be specified at specific times. If you have a
prologue like this:
__Z3fooi:
Leh_func_begin1:
LBB1_0: ## entry
pushl %ebp
Llabel1:
movl %esp, %ebp
Llabel2:
pushl %esi
Llabel3:
subl $20, %esp
call "L1$pb"
"L1$pb":
popl %esi
The "pushl %ebp" needs a table entry specifying the offset. The "movl %esp,
%ebp" makes %ebp the new stack frame register, so that needs to be specified in
DWARF. And "pushl %esi" saves the callee-saved %esi register, which also needs
to be specified in DWARF.
Before, all of this logic was in one method. This didn't work too well, because
as you can see there are multiple FDE line entries that need to be created.
This fix creates the "MachineMove" objects directly when they're needed; instead
of waiting until the end, and losing information.
There is some ugliness where we generate code like this:
LBB22_0: ## entry
pushl %ebp
Llabel280:
movl %esp, %ebp
Llabel281:
Llabel284:
pushl %ebp <----------
pushl %ebx
pushl %edi
pushl %esi
Llabel282:
subl $328, %esp
Notice the extra "pushl %ebp". If we generate a "machine move" instruction in
the FDE for that pushl, the linker may get very confused about what value %ebp
should have when exitting the function. I.e., it'll give it the value %esp
instead of the %ebp value from the first "pushl". Not to mention that, in this
case, %ebp isn't modified in the function (that's a separate bug). I put a small
hack in to get it to work. It might be the only solution, but should be
revisited once the above case is fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75047 91177308-0d34-0410-b5e6-96231b3b80d8
U lib/Target/X86/X86RegisterInfo.cpp
U lib/Target/X86/X86RegisterInfo.h
Temporarily revert. This was causing an infinite loop in the linker on Leopard.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74970 91177308-0d34-0410-b5e6-96231b3b80d8
prologue like this:
__Z3fooi:
Leh_func_begin1:
LBB1_0: ## entry
pushl %ebp
Llabel1:
movl %esp, %ebp
Llabel2:
pushl %esi
Llabel3:
subl $20, %esp
call "L1$pb"
"L1$pb":
popl %esi
The "pushl %ebp" needs a table entry specifying the offset. The "movl %esp,
%ebp" makes %ebp the new stack frame register, so that needs to be specified in
DWARF. And "pushl %esi" saves the callee-saved %esi register, which also needs
to be specified in DWARF.
Before, all of this logic was in one method. This didn't work too well, because
as you can see there are multiple FDE line entries that need to be created.
This fix creates the "MachineMove" objects directly when they're needed; instead
of waiting until the end, and losing information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74952 91177308-0d34-0410-b5e6-96231b3b80d8
- Add patterns for h-register extract, which avoids a shift and mask,
and in some cases a temporary register.
- Add address-mode matching for turning (X>>(8-n))&(255<<n), where
n is a valid address-mode scale value, into an h-register extract
and a scaled-offset address.
- Replace X86's MOV32to32_ and related instructions with the new
target-independent COPY_TO_SUBREG instruction.
On x86-64 there are complicated constraints on h registers, and
CodeGen doesn't currently provide a high-level way to express all of them,
so they are handled with a bunch of special code. This code currently only
supports extracts where the result is used by a zero-extend or a store,
though these are fairly common.
These transformations are not always beneficial; since there are only
4 h registers, they sometimes require extra move instructions, and
this sometimes increases register pressure because it can force out
values that would otherwise be in one of those registers. However,
this appears to be relatively uncommon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68962 91177308-0d34-0410-b5e6-96231b3b80d8
and better control the abstraction. Rename the type
to MVT. To update out-of-tree patches, the main
thing to do is to rename MVT::ValueType to MVT, and
rewrite expressions like MVT::getSizeInBits(VT) in
the form VT.getSizeInBits(). Use VT.getSimpleVT()
to extract a MVT::SimpleValueType for use in switch
statements (you will get an assert failure if VT is
an extended value type - these shouldn't exist after
type legalization).
This results in a small speedup of codegen and no
new testsuite failures (x86-64 linux).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52044 91177308-0d34-0410-b5e6-96231b3b80d8
Change insert/extract subreg instructions to be able to be used in TableGen patterns.
Use the above features to reimplement an x86-64 pseudo instruction as a pattern.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48130 91177308-0d34-0410-b5e6-96231b3b80d8
to use different mappings for EH and debug info;
no functional change yet.
Fix warning in X86CodeEmitter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44056 91177308-0d34-0410-b5e6-96231b3b80d8
This makes DwarfRegNum to accept list of numbers instead.
Added three different "flavours", but only slightly tested on x86-32/linux.
Please check another subtargets if possible,
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43997 91177308-0d34-0410-b5e6-96231b3b80d8
Turn a store folding instruction into a load folding instruction. e.g.
xorl %edi, %eax
movl %eax, -32(%ebp)
movl -36(%ebp), %eax
orl %eax, -32(%ebp)
=>
xorl %edi, %eax
orl -36(%ebp), %eax
mov %eax, -32(%ebp)
This enables the unfolding optimization for a subsequent instruction which will
also eliminate the newly introduced store instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43192 91177308-0d34-0410-b5e6-96231b3b80d8
register used by the unfolded instructions. User can also specify whether to
unfold the load, the store, or both.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42946 91177308-0d34-0410-b5e6-96231b3b80d8
in the trampoline lowering. Lookup the jump and
mov opcodes for the trampoline rather than hard
coding them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41577 91177308-0d34-0410-b5e6-96231b3b80d8
This patch fills the last necessary bits to enable exceptions
handling in LLVM. Currently only on x86-32/linux.
In fact, this patch adds necessary intrinsics (and their lowering) which
represent really weird target-specific gcc builtins used inside unwinder.
After corresponding llvm-gcc patch will land (easy) exceptions should be
more or less workable. However, exceptions handling support should not be
thought as 'finished': I expect many small and not so small glitches
everywhere.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39855 91177308-0d34-0410-b5e6-96231b3b80d8
