on CodeGen/X86/2007-05-07-InvokeSRet.ll. There is probably a bug here that was
fixed by r128961, but since there is no test or reference to a source file I have
to revert it.
llvm-svn: 131618
LiveInterval::shrinkToUses recomputes the live range from scratch instead of
removing snippets. This should avoid the problem with dangling live ranges.
Leave physreg identity copies alone. They can be created when joining a virtreg
with a physreg. They don't affect register allocation, and they will be removed
by the rewriter.
llvm-svn: 131521
The greedy register allocator has live range splitting and register class
inflation, so it can actually fully undo this join, including restoring the
original register classes.
We still don't want to do this for long live ranges, mostly because of the high
register pressure of there are many constrained live ranges overlapping.
llvm-svn: 131466
When instructions are deleted, they leave tombstone SlotIndex entries.
The isZeroLength method should ignore these null indexes.
This causes RABasic to sometimes spill a callee-saved register in the
abi-isel.ll test, so don't run that test with -regalloc=basic. Prioritizing
register allocation according to spill weight can cause more registers to be
used.
llvm-svn: 131436
by non-CMP expressions. The executable test case (129821) would test
this as well, if we had an "-O0 -disable-arm-fast-isel" LLVM-GCC
tester. Alas, the ARM assembly would be very difficult to check with
FileCheck.
The thumb2-cbnz.ll test is affected; it generates larger code (tst.w
vs. cmp #0), but I believe the new version is correct.
rdar://problem/9298790
llvm-svn: 131261
about to be spilled.
This can only happen when two extra snippet registers are included in the spill,
and there is a copy between them. Hoisting the spill creates problems because
the hoist will mark the copy for later dead code elimination, and spilling the
second register will turn the copy into a spill.
<rdar://problem/9420853>
llvm-svn: 131192
If there is a store after the load node, then there is a chain, which means
that there is another user. Thus, asking hasOneUser would fail. Instead we
ask hasNUsesOfValue on the 'data' value.
llvm-svn: 131183
intrinsic call. This prevents it from being reordered so that it appears
*before* the setjmp intrinsic (thus making it completely useless).
<rdar://problem/9409683>
llvm-svn: 131174
at the start of basic blocks to their common predecessor. It's actually quite
common (e.g. about 50 times in JM/lencod) and has shown to be a nice code size
benefit. e.g.
pushq %rax
testl %edi, %edi
jne LBB0_2
## BB#1:
xorb %al, %al
popq %rdx
ret
LBB0_2:
xorb %al, %al
callq _foo
popq %rdx
ret
=>
pushq %rax
xorb %al, %al
testl %edi, %edi
je LBB0_2
## BB#1:
callq _foo
LBB0_2:
popq %rdx
ret
rdar://9145558
llvm-svn: 131172
this clang will use .debug_frame in, for example,
clang -g -c -m32 test.c
This matches gcc's behaviour. It looks like .debug_frame is a bit bigger
than .eh_frame, but has the big advantage of not being allocated.
llvm-svn: 131140
It can happen that a live debug variable is the last use of a sub-register, and
the register allocator will pick a larger register class for the virtual
register. If the allocated register doesn't support the sub-register index,
just use %noreg for the debug variables instead of asserting.
In PR9872, a debug variable ends up in the sub_8bit_hi part of a GR32_ABCD
register. The register is split and one part is inflated to GR32 and assigned
%ESI because there are no more normal uses of sub_8bit_hi.
Since %ESI doesn't have that sub-register, substPhysReg asserted. Now it will
simply insert a %noreg instead, and the debug variable will be marked
unavailable in that range.
We don't currently have a way of saying: !"value" is in bits 8-15 of %ESI, I
don't know if DWARF even supports that.
llvm-svn: 131073
Cameron Zwarich