[LLVMdev] [ARM backend] adding pattern for SMLALBB

[Jyoti Rajendra Allur]

Hi James/Tim,
I am trying to add a patterns for SMLALBB

I think these two assembly patterns can be reduced to SMLALBB using tablegen.

1) 
smulbb  r2, r3, r2
adds    r0, r2, r0 (RdLo)
asr     r3, r2, #31
adc     r1, r3, r1 (RdHi)   ==> smlalbb r0, r1, r3, r2 

I have added pattern in def SMLALBB : AMulxyI64< .....                  as below :-
[] modified to ---> [((set GPR:$RdLo, (ARMaddc (set GPR:$Rd, mul GPR:$Rn, GPR:$Rm), GPR:$RdLo)), (set GPR:$RdHi, (ARMadde (sra GPR:$Rd, (i32 31)), GPR:$RdHi,  CPSR)))]
This results in 'expected identifier in dag init' error.

Obviously something is wrong in this pattern, I have not figured out what that is ?


2)
ldrb r2, [r2]
ldrb r3, [r3]
smlal r0, r1, r3, r2     ==> smlalbb r0, r1, r3, r2 
def : ARMV5MOPat<(smlal GPRnopc:$RdLo, GPRnopc:$RdHi,
                        (sra (shl GPR:$a, (i32 24)), (i32 24)),
                           (sra (shl GPR:$b, (i32 24)), (i32 24))),
                 (SMLALBB GPRnopc:$RdLo, GPRnopc:$RdHi, GPRnopc:$Rn, GPRnopc:Rm)>;

This throws "Variable not defined: 'smlal' 

Any pointers on these would be helpful.

Regards,
Jyoti Allur