This patch changes the definition of negative from -0..-255 to -1..-255. I am changing this because of
a bug that we had in some of the patterns that assumed that "subs" of zero does not set the carry flag.
rdar://12028498
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167963 91177308-0d34-0410-b5e6-96231b3b80d8
mov lr, pc
b.w _foo
The "mov" instruction doesn't set bit zero to one, it's putting incorrect
value in lr. It messes up backtraces.
rdar://12663632
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167657 91177308-0d34-0410-b5e6-96231b3b80d8
When the operand is a plain immediate rather than a label, print it
as [pc, #imm] like we do for the Thumb2 wide encoding variant.
rdar://12154503
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166991 91177308-0d34-0410-b5e6-96231b3b80d8
is 24 bits not 20 and the decoding needed to correctly handle converting the
J1 and J2 bits to their I1 and I2 values to reconstruct the displacement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166982 91177308-0d34-0410-b5e6-96231b3b80d8
into a sbc with a positive number, the immediate should be complemented, not
negated. Also added a missing pattern for ARM codegen.
rdar://12559385
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166613 91177308-0d34-0410-b5e6-96231b3b80d8
These pseudos are no longer needed now that it is possible to represent
predicated instructions in SSA form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163275 91177308-0d34-0410-b5e6-96231b3b80d8
This patch corrects the definition of umlal/smlal instructions and adds support
for matching them to the ARM dag combiner.
Bug 12213
Patch by Yin Ma!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163136 91177308-0d34-0410-b5e6-96231b3b80d8
This wasn't the right way to enforce ordering of atomics.
We are already setting the isVolatile bit on memory operands of atomic
operations which is good enough to enforce the correct ordering.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162732 91177308-0d34-0410-b5e6-96231b3b80d8
It is not safe to use normal LDR instructions because they may be
reordered by the scheduler. The ATOMIC_LDR pseudos have a mayStore flag
that prevents reordering.
Atomic loads are also prevented from participating in rematerialization
and load folding.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162713 91177308-0d34-0410-b5e6-96231b3b80d8
It's not clear that they should be marked as such, but tbb formation
fails if t2LEApcrelJT is hoisted of of a loop.
This doesn't change the flags on these instructions,
UnmodeledSideEffects was already inferred from the missing pattern.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162603 91177308-0d34-0410-b5e6-96231b3b80d8
It is not my plan to duplicate the entire ARM instruction set with
predicated versions. We need a way of representing predicated
instructions in SSA form without requiring a separate opcode.
Then the pseudo-instructions can go away.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162061 91177308-0d34-0410-b5e6-96231b3b80d8
The ARM select instructions are just predicated moves. If the select is
the only use of an operand, the instruction defining the operand can be
predicated instead, saving one instruction and decreasing register
pressure.
This implementation can turn AND/ORR/EOR instructions into their
corresponding ANDCC/ORRCC/EORCC variants. Ideally, we should be able to
predicate any instruction, but we don't yet support predicated
instructions in SSA form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161994 91177308-0d34-0410-b5e6-96231b3b80d8
When predicating this instruction:
Rd = ADD Rn, Rm
We need an extra operand to represent the value given to Rd when the
predicate is false:
Rd = ADDCC Rfalse, Rn, Rm, pred
The Rd and Rfalse operands are different registers while in SSA form.
Rfalse is tied to Rd to make sure they get the same register during
register allocation.
Previously, Rd and Rn were tied, but that is not required.
Compare to MOVCC:
Rd = MOVCC Rfalse, Rtrue, pred
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161955 91177308-0d34-0410-b5e6-96231b3b80d8
architecture
It broke MultiSource/Applications/JM/ldecod/ldecod on armv7 thumb O0 g and armv7
thumb O3.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161736 91177308-0d34-0410-b5e6-96231b3b80d8
This patch corrects the definition of umlal/smlal instructions and adds support
for matching them to the ARM dag combiner.
Bug 12213
Patch by Yin Ma!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161581 91177308-0d34-0410-b5e6-96231b3b80d8
Now that TableGen supports references to NAME w/o it being explicitly
referenced in the definition's own name, use that to simplify
assembly InstAlias definitions in multiclasses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161218 91177308-0d34-0410-b5e6-96231b3b80d8
Function argument registers are added to the call SDNode, but
InstrEmitter now knows how to make those operands implicit, and the call
instruction doesn't have to be variadic.
Explicit register operands should only be those that are encoded in the
instruction, implicit register operands are for extra dependencies like
call argument and return values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160188 91177308-0d34-0410-b5e6-96231b3b80d8
There are patterns to handle immediates when they fit in the immediate field.
e.g. %sub = add i32 %x, -123
=> sub r0, r0, #123
Add patterns to catch immediates that do not fit but should be materialized
with a single movw instruction rather than movw + movt pair.
e.g. %sub = add i32 %x, -65535
=> movw r1, #65535
sub r0, r0, r1
rdar://11726136
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159057 91177308-0d34-0410-b5e6-96231b3b80d8
The NOP, WFE, WFI, SEV and YIELD instructions are all hints w/
a different immediate value in bits [7,0]. Define a generic HINT
instruction and refactor NOP, WFI, WFI, SEV and YIELD to be
assembly aliases of that.
rdar://11600518
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158674 91177308-0d34-0410-b5e6-96231b3b80d8
when a compile time constant is known. This occurs when implicitly zero
extending function arguments from 16 bits to 32 bits. The 8 bit case doesn't
need to be handled, as the 8 bit constants are encoded directly, thereby
not needing a separate load instruction to form the constant into a register.
<rdar://problem/11481151>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158659 91177308-0d34-0410-b5e6-96231b3b80d8
We turned off the CMN instruction because it had semantics which we weren't
getting correct. If we are comparing with an immediate, then it's okay to use
the CMN instruction.
<rdar://problem/7569620>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158302 91177308-0d34-0410-b5e6-96231b3b80d8
when a compile time constant is known. This occurs when implicitly zero
extending function arguments from 16 bits to 32 bits.
<rdar://problem/11481151>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157966 91177308-0d34-0410-b5e6-96231b3b80d8
the 0b10 mask encoding bits. Make MSR APSR writes without a _<bits> qualifier
an alias for MSR APSR_nzcvq even though ARM as deprecated it use. Also add
support for suffixes (_nzcvq, _g, _nzcvqg) for APSR versions. Some FIXMEs in
the code for better error checking when versions shouldn't be used.
rdar://11457025
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157019 91177308-0d34-0410-b5e6-96231b3b80d8
We were incorrectly conflating some add variants which don't have a
cc_out operand with the mirroring sub encodings, which do. Part of the
awesome non-orthogonality legacy of thumb1. Similarly, handling of
add/sub of an immediate was sometimes incorrectly removing the cc_out
operand for add/sub register variants.
rdar://11216577
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154411 91177308-0d34-0410-b5e6-96231b3b80d8
We had special instructions for iOS because r9 is call-clobbered, but
that is represented dynamically by the register mask operands now, so
there is no need for the pseudo-instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154144 91177308-0d34-0410-b5e6-96231b3b80d8
'add r2, #-1024' should just use 'sub r2, #1024' rather than erroring out.
Thumb1 aliases for adding a negative immediate to the stack pointer,
also.
rdar://11192734
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154123 91177308-0d34-0410-b5e6-96231b3b80d8
A MOVCCr instruction can be commuted by inverting the condition. This
can help reduce register pressure and remove unnecessary copies in some
cases.
<rdar://problem/11182914>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154033 91177308-0d34-0410-b5e6-96231b3b80d8
The CMP->CMN alias was matching for an immediate of zero when it
should only match for negative values.
rdar://11129224
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153689 91177308-0d34-0410-b5e6-96231b3b80d8
the processor keeps a return addresses stack (RAS) which stores the address
and the instruction execution state of the instruction after a function-call
type branch instruction.
Calling a "noreturn" function with normal call instructions (e.g. bl) can
corrupt RAS and causes 100% return misprediction so LLVM should use a
unconditional branch instead. i.e.
mov lr, pc
b _foo
The "mov lr, pc" is issued in order to get proper backtrace.
rdar://8979299
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151623 91177308-0d34-0410-b5e6-96231b3b80d8
I'll let the buildbots determine the compile time improvements from this
change, but 464.h264ref has 5% faster codegen at -O2.
This patch does cause some assembly changes. Branch folding can make
different decisions about calls with dead return values.
CriticalAntiDepBreaker may choose different registers because its
liveness tracking is affected. MachineCopyPropagation may sometimes
leave a dead copy behind.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151331 91177308-0d34-0410-b5e6-96231b3b80d8
value is zero. Instead of a cmov + op, issue an conditional op instead. e.g.
cmp r9, r4
mov r4, #0
moveq r4, #1
orr lr, lr, r4
should be:
cmp r9, r4
orreq lr, lr, #1
That is, optimize (or x, (cmov 0, y, cond)) to (or.cond x, y). Similarly extend
this to xor as well as (and x, (cmov -1, y, cond)) => (and.cond x, y).
It's possible to extend this to ADD and SUB but I don't think they are common.
rdar://8659097
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151224 91177308-0d34-0410-b5e6-96231b3b80d8