This automagically provides a transform noticed by my super-optimizer
as occurring quite often: "rem x, (select cond, x, 1)" -> 0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130694 91177308-0d34-0410-b5e6-96231b3b80d8
When an interfering live range ends at a dead slot index between two
instructions, make sure that the inserted copy instruction gets a slot index
after the dead ones. This makes it possible to avoid the interference.
Ideally, there shouldn't be interference ending at a deleted instruction, but
physical register coalescing can sometimes do that to sub-registers.
This fixes PR9823.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130687 91177308-0d34-0410-b5e6-96231b3b80d8
This makes a difference if a live interval is referring to a deleted
instruction. It can be important to insert an instruction before or after a
deleted instruction to avoid interference.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130686 91177308-0d34-0410-b5e6-96231b3b80d8
comments claimed it did this, but the LHS value was actually an unused variable.
The new system considers only the '-foo' part when comparing it for typos
against flags that have values, but still look at the whole string for flags
that don't. That way, we'll still correct '-inst=combine' to '-instcombine'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130685 91177308-0d34-0410-b5e6-96231b3b80d8
for all symbol differences and can drop the old EmitPCRelSymbolValue
method.
This also make getExprForFDESymbol on ELF equal to the one on MachO, and it
can be made non-virtual.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130634 91177308-0d34-0410-b5e6-96231b3b80d8
after folding ADD32ri to ADD32mi, so don't do that.
This only happens when the greedy register allocator gets itself in trouble and
spills %vreg9 here:
16L %vreg9<def> = MOVPC32r 0, %ESP<imp-use>; GR32:%vreg9
48L %vreg9<def> = ADD32ri %vreg9, <es:_GLOBAL_OFFSET_TABLE_>[TF=1], %EFLAGS<imp-def,dead>; GR32:%vreg9
That should never happen, the live range should be split instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130625 91177308-0d34-0410-b5e6-96231b3b80d8
Currently the output should be almost identical to the one produced by CodeGen
to make the transition easier.
The only two differences I know of are:
* Some files get an extra advance loc of size 0. This will be fixed when
relaxations are enabled.
* The optimization of declaring an EH symbol as an external variable is not
implemented. This is a subset of adding the nounwind attribute, so we if really
this at -O0 we should probably do it at the IL level.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130623 91177308-0d34-0410-b5e6-96231b3b80d8
This obviously helps a lot if the division would be turned into a libcall
(think i64 udiv on i386), but div is also one of the few remaining instructions
on modern CPUs that become more expensive when the bitwidth gets bigger.
This also helps register pressure on i386 when dividing chars, divb needs
two 8-bit parts of a 16 bit register as input where divl uses two registers.
int foo(unsigned char a) { return a/10; }
int bar(unsigned char a, unsigned char b) { return a/b; }
compiles into (x86_64)
_foo:
imull $205, %edi, %eax
shrl $11, %eax
ret
_bar:
movzbl %dil, %eax
divb %sil, %al
movzbl %al, %eax
ret
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130615 91177308-0d34-0410-b5e6-96231b3b80d8
is a bit ugly, but doing it on the base MCStreamer would be redundant
with the object streamer which does it using SD.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130611 91177308-0d34-0410-b5e6-96231b3b80d8
This could happen when trying to use a value that had been eliminated after dead
code elimination and folding loads.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130597 91177308-0d34-0410-b5e6-96231b3b80d8
