slots. The AsmPrinter will use this information to determine whether to
print a spill/reload comment.
Remove default argument values. It's too easy to pass a wrong argument
value when multiple arguments have default values. Make everything
explicit to trap bugs early.
Update all targets to adhere to the new interfaces..
llvm-svn: 87022
a virtual register to eliminate a frame index, it can return that register
and the constant stored there to PEI to track. When scavenging to allocate
for those registers, PEI then tracks the last-used register and value, and
if it is still available and matches the value for the next index, reuses
the existing value rather and removes the re-materialization instructions.
Fancier tracking and adjustment of scavenger allocations to keep more
values live for longer is possible, but not yet implemented and would likely
be better done via a different, less special-purpose, approach to the
problem.
eliminateFrameIndex() is modified so the target implementations can return
the registers they wish to be tracked for reuse.
ARM Thumb1 implements and utilizes the new mechanism. All other targets are
simply modified to adjust for the changed eliminateFrameIndex() prototype.
llvm-svn: 83467
what was there before. In "no FP mode", we weren't generating labels and unwind
table entries after each "push" instruction. While more than likely "okay", it's
not technically correct. The major thing was that the ordering of when to define
a new CFA register and at what offset wasn't correct. This would cause the
exception handling to fail in ways most miserable to users.
I also cleaned up some code a bit. There's one function which has a "return" at
the beginning, so it's never used. Should I just remove it? :-)
llvm-svn: 79139
pushes in the function prolog if the function doesn't have any stack space,
i.e. for a prolog like:
0x40011870: push %r15
0x40011872: push %r14
0x40011874: push %rbx
Patch by Zoltan!
llvm-svn: 77919
testsuite, due to exception handling not working
correctly. Maybe because the libgcc unwinder is
miscompiled - not sure, and I won't have time to
look into it before leaving on holiday. Note that
miscompilations of libgcc are not picked up by the
nightly testers, because they dynamically link with
libgcc, so pick up the system version rather than
the version built as part of llvm-gcc. This is a
nasty flaw in the nightly testers. (On the other
hand the Ada testsuite links with the just built
libgcc).
llvm-svn: 76895
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").
llvm-svn: 75640
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.
llvm-svn: 75379
is modified. Otherwise, the unwinder will get confused. The old code (before I
started my hacking) did this. It dropped on the floor, because I wasn't aware of
this requirement.
On the plus side, if we use "alloca" in a function, we create frame pointers
even with -fomit-frame-pointer is enabled!
This is a Good Thing(tm)!!!
llvm-svn: 75183
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.
llvm-svn: 75116
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.
llvm-svn: 75047
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.
llvm-svn: 74970
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.
llvm-svn: 74952
comes after the DW_CFA_def_cfa_register, because the CFA is really ESP from the
start of the function and only gets an offset when the "subl $xxx,%esp"
instruction happens, not the other way around.
And reapply r72898:
The DWARF unwind info was incorrect. While compiling with
`-fomit-frame-pointer', we would lack the DW_CFA_advance_loc information for a
lot of function, and then they would be `0'. The linker (at least on Darwin)
needs to encode the stack size. In some cases, the stack size is too large to
directly encode. So the linker checks to see if there is a "subl $xxx,%esp"
instruction at the point where the `DW_CFA_def_cfa_offset' says the pc was. If
so, the compact encoding records the offset in the function to where the stack
size is embedded. But because the `DW_CFA_advance_loc' instructions are missing,
it looks before the function and dies.
So, instead of emitting the EH debug label before the stack adjustment
operations, emit it afterwards, right before the frame move stuff.
llvm-svn: 73465
`-fomit-frame-pointer', we would lack the DW_CFA_advance_loc information for a
lot of function, and then they would be `0'. The linker (at least on Darwin)
needs to encode the stack size. In some cases, the stack size is too large to
directly encode. So the linker checks to see if there is a "subl $xxx,%esp"
instruction at the point where the `DW_CFA_def_cfa_offset' says the pc was. If
so, the compact encoding records the offset in the function to where the stack
size is embedded. But because the `DW_CFA_advance_loc' instructions are missing,
it looks before the function and dies.
So, instead of emitting the EH debug label before the stack adjustment
operations, emit it afterwards, right before the frame move stuff.
llvm-svn: 72898
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.
llvm-svn: 72894
booleans. This gives a better indication of what the "addReg()" is
doing. Remembering what all of those booleans mean isn't easy, especially if you
aren't spending all of your time in that code.
I took Jakob's suggestion and made it illegal to pass in "true" for the
flag. This should hopefully prevent any unintended misuse of this (by reverting
to the old way of using addReg()).
llvm-svn: 71722
builds.
--- Reverse-merging (from foreign repository) r68552 into '.':
U test/CodeGen/X86/tls8.ll
U test/CodeGen/X86/tls10.ll
U test/CodeGen/X86/tls2.ll
U test/CodeGen/X86/tls6.ll
U lib/Target/X86/X86Instr64bit.td
U lib/Target/X86/X86InstrSSE.td
U lib/Target/X86/X86InstrInfo.td
U lib/Target/X86/X86RegisterInfo.cpp
U lib/Target/X86/X86ISelLowering.cpp
U lib/Target/X86/X86CodeEmitter.cpp
U lib/Target/X86/X86FastISel.cpp
U lib/Target/X86/X86InstrInfo.h
U lib/Target/X86/X86ISelDAGToDAG.cpp
U lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
U lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.cpp
U lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.h
U lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.h
U lib/Target/X86/X86ISelLowering.h
U lib/Target/X86/X86InstrInfo.cpp
U lib/Target/X86/X86InstrBuilder.h
U lib/Target/X86/X86RegisterInfo.td
llvm-svn: 68560
This introduces a small regression on the generated code
quality in the case we are just computing addresses, not
loading values.
Will work on it and on X86-64 support.
llvm-svn: 68552
