t2LDRpci with t2LDRi12.
There are a couple of problems with this.
1. The encoding for the literal and immediate constant are different.
Note bit 7 of the literal case is 'U' so it can be negative.
2. t2LDRi12 is now narrowed to tLDRpci before constant island pass is run.
So we end up never using the Thumb2 instruction, which ends up creating a
lot more constant islands.
llvm-svn: 125074
instruction based on the t_addrmode_s# mode and what it returned. There is some
obvious badness to this. In particular, it's hard to do MC-encoding when the
instruction may change out from underneath you after the t_addrmode_s# variable
is finally resolved.
The solution is to revert a long-ago change that merged the reg/reg and reg/imm
versions. There is the addition of several new addressing modes. They no longer
have extraneous operands associated with them. I.e., if it's reg/reg we don't
have to have a dummy zero immediate tacked on to the SDNode.
There are some obvious cleanups here, which will happen shortly.
llvm-svn: 121747
'db', 'ib', 'da') instead of having that mode as a separate field in the
instruction. It's more convenient for the asm parser and much more readable for
humans.
<rdar://problem/8654088>
llvm-svn: 119310
register must be one of the destination registers for the load. Otherwise,
the tLDM instruction will write-back to the base register, which isn't what's
desired (otherwise, we'd have a t2LDM_UPD instead).
rdar://8394087
llvm-svn: 113297
writebacks to the address register. This gets rid of the hack that the
first register on the list was the magic writeback register operand. There
was an implicit constraint that if that operand was not reg0 it had to match
the base register operand. The post-RA scheduler's antidependency breaker
did not understand that constraint and sometimes changed one without the
other. This also fixes Radar 7495976 and should help the verifier work
better for ARM code.
There are now new ld/st instructions explicit writeback operands and explicit
constraints that tie those registers together.
llvm-svn: 98409
tMOVCCi pattern only valid for low registers, as the Thumb1 mov immediate to
register instruction only works with low registers. Allowing high registers
for the instruction resulted in the assembler choosing the wide (32-bit)
encoding for the mov, but LLVM though the instruction was only 16 bits wide,
so offset calculations for constant pools became incorrect, leading to
out of range constant pool entries.
llvm-svn: 95686
than doing the same via constpool:
1. Load from constpool costs 3 cycles on A9, movt/movw pair - just 2.
2. Load from constpool might stall up to 300 cycles due to cache miss.
3. Movt/movw does not use load/store unit.
4. Less constpool entries => better compiler performance.
This is only enabled on ELF systems, since darwin does not have needed
relocations (yet).
llvm-svn: 89720
instruction. This makes it re-materializable.
Thumb2 will split it back out into two instructions so IT pass will generate the
right mask. Also, this expose opportunies to optimize the movw to a 16-bit move.
llvm-svn: 82982
MachineInstr and MachineOperand. This required eliminating a
bunch of stuff that was using DOUT, I hope that bill doesn't
mind me stealing his fun. ;-)
llvm-svn: 79813
match base only address, i.e. [r] since Thumb2 requires a offset register field.
For those, use [r + imm12] where the immediate is zero.
Note the generated assembly code does not look any different after the patch.
But the bug would have broken the JIT (if there is Thumb2 support) and it can
break later passes which expect the address mode to be well-formed.
llvm-svn: 78658
Bob Wilson