use the zero-undefined variants of CTTZ and CTLZ. These are just simple
patterns for now, there is more to be done to make real world code using
these constructs be optimized and codegen'ed properly on X86.
The existing tests are spiffed up to check that we no longer generate
unnecessary cmov instructions, and that we generate the very important
'xor' to transform bsr which counts the index of the most significant
one bit to the number of leading (most significant) zero bits. Also they
now check that when the variant with defined zero result is used, the
cmov is still produced.
llvm-svn: 146974
We used to rely on the *eh_sjlj_setjmp instructions to mark that a function
with setjmp/longjmp exception handling clobbers all the registers. But with
the recent reorganization of ARM EH, those eh_sjlj_setjmp instructions are
expanded away earlier, before PEI can see them to determine what registers to
save and restore. Mark the dispatchsetup instruction in the same way, since
that instruction cannot be expanded early. This also more accurately reflects
when the registers are clobbered.
llvm-svn: 146949
"mov r1, r2, lsl #0" should assemble as "mov r1, r2" even though it's
not strictly legal UAL syntax. It's a common extension and the friendly
thing to do.
rdar://10604663
llvm-svn: 146937
merging types by name when we can. We still don't guarantee type name linkage
but we do it when obviously the right thing to do. This makes LTO type names
easier to read, for example.
llvm-svn: 146932
unpredicated. That is, turn
subeq r0, r1, #1
addne r0, r1, #1
into
sub r0, r1, #1
addne r0, r1, #1
For targets where conditional instructions are always executed, this may be
beneficial. It may remove pseudo anti-dependency in out-of-order execution
CPUs. e.g.
op r1, ...
str r1, [r10] ; end-of-life of r1 as div result
cmp r0, #65
movne r1, #44 ; raw dependency on previous r1
moveq r1, #12
If movne is unpredicated, then
op r1, ...
str r1, [r10]
cmp r0, #65
mov r1, #44 ; r1 written unconditionally
moveq r1, #12
Both mov and moveq are no longer depdendent on the first instruction. This gives
the out-of-order execution engine more freedom to reorder them.
This has passed entire LLVM test suite. But it has not been enabled for any ARM
variant pending more performance evaluation.
rdar://8951196
llvm-svn: 146914
This change reduces the number of instructions generated.
For example,
(load (add (sub $n0, $n1), (MipsLo got(s))))
results in the following sequence of instructions:
1. sub $n2, $n0, $n1
2. lw got(s)($n2)
Previously, three instructions were needed.
1. sub $n2, $n0, $n1
2. addiu $n3, $n2, got(s)
3. lw 0($n3)
llvm-svn: 146888
Now that getMatchingSuperRegClass() returns accurate results, it can be
used to compute constraints imposed by instructions using a sub-register
of a virtual register.
This means we can recompute the register class of any virtual register
by combining the constraints from all its uses.
llvm-svn: 146874
Use information computed while inferring new register classes to emit
accurate, table-driven implementations of getMatchingSuperRegClass().
Delete the old manual, error-prone implementations in the targets.
llvm-svn: 146873
Teach TableGen to create the missing register classes needed for
getMatchingSuperRegClass() to return maximal results. The function is
still not auto-generated, so it still returns inexact results.
This produces these new register classes:
ARM:
QQPR_with_dsub_0_in_DPR_8
QQQQPR_with_dsub_0_in_DPR_8
X86:
GR64_with_sub_32bit_in_GR32_NOAX
GR64_with_sub_32bit_in_GR32_NOAX_and_GR32_NOSP
GR64_with_sub_16bit_in_GR16_NOREX
GR64_with_sub_32bit_in_GR32_NOAX_and_GR32_NOREX
GR64_TC_and_GR64_with_sub_32bit_in_GR32_NOAX
GR64_with_sub_32bit_in_GR32_NOAX_and_GR32_NOREX_NOSP
GR64_TCW64_and_GR64_with_sub_32bit_in_GR32_NOAX
GR64_TC_and_GR64_with_sub_32bit_in_GR32_NOAX_and_GR32_NOREX
GR64_with_sub_32bit_in_GR32_TC
GR64_with_sub_32bit_in_GR32_ABCD_and_GR32_NOAX
GR64_with_sub_32bit_in_GR32_NOAX_and_GR32_TC
GR64_with_sub_32bit_in_GR32_AD
GR64_with_sub_32bit_in_GR32_AD_and_GR32_NOAX
The other targets in the tree are not weird enough to be affected.
llvm-svn: 146872
