frame index reference to an object in the local block is seen, check if
it's near enough to any previously allocaated base register to re-use.
rdar://8277890
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111443 91177308-0d34-0410-b5e6-96231b3b80d8
Nothing fancy, just ask the target if any currently available base reg
is in range for the instruction under consideration and use the first one
that is. Placeholder ARM implementation simply returns false for now.
ongoing saga of rdar://8277890
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111374 91177308-0d34-0410-b5e6-96231b3b80d8
the local block. Resolve references to those indices to a new base register.
For simplification and testing purposes, a new virtual base register is
allocated for each frame index being resolved. The result is truly horrible,
but correct, code that's good for exercising the new code paths.
Next up is adding thumb1 support, which should be very simple. Following that
will be adding base register re-use and implementing a reasonable ARM
heuristic for when a virtual base register should be generated at all.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111315 91177308-0d34-0410-b5e6-96231b3b80d8
whether to allocate a virtual frame base register to resolve the frame
index reference in it. Implement a simple version for ARM to aid debugging.
In LocalStackSlotAllocation, scan the function for frame index references
to local frame indices and ask the target whether to allocate virtual
frame base registers for any it encounters. Purely infrastructural for
debug output. Next step is to actually allocate base registers, then add
intelligent re-use of them.
rdar://8277890
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111262 91177308-0d34-0410-b5e6-96231b3b80d8
printing "lsl #0". This fixes the remaining parts of pr7792. Make
corresponding changes for encoding/decoding these instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111251 91177308-0d34-0410-b5e6-96231b3b80d8
the memory barrier variants (other than 'SY' full system domain read and write)
are treated as one instruction with option operand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110951 91177308-0d34-0410-b5e6-96231b3b80d8
entry for ARM STRBT is actually a super-instruction for A8.6.199 STRBT A1 & A2.
Recover by looking for ARM:USAT encoding pattern before delegating to the auto-
gened decoder.
Added a "usat" test case to arm-tests.txt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110894 91177308-0d34-0410-b5e6-96231b3b80d8
float t1(int argc) {
return (argc == 1123) ? 1.234f : 2.38213f;
}
We would generate truly awful code on ARM (those with a weak stomach should look
away):
_t1:
movw r1, #1123
movs r2, #1
movs r3, #0
cmp r0, r1
mov.w r0, #0
it eq
moveq r0, r2
movs r1, #4
cmp r0, #0
it ne
movne r3, r1
adr r0, #LCPI1_0
ldr r0, [r0, r3]
bx lr
The problem was that legalization was creating a cascade of SELECT_CC nodes, for
for the comparison of "argc == 1123" which was fed into a SELECT node for the ?:
statement which was itself converted to a SELECT_CC node. This is because the
ARM back-end doesn't have custom lowering for SELECT nodes, so it used the
default "Expand".
I added a fairly simple "LowerSELECT" to the ARM back-end. It takes care of this
testcase, but can obviously be expanded to include more cases.
Now we generate this, which looks optimal to me:
_t1:
movw r1, #1123
movs r2, #0
cmp r0, r1
adr r0, #LCPI0_0
it eq
moveq r2, #4
ldr r0, [r0, r2]
bx lr
.align 2
LCPI0_0:
.long 1075344593 @ float 2.382130e+00
.long 1067316150 @ float 1.234000e+00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110799 91177308-0d34-0410-b5e6-96231b3b80d8
