Improve Thumb2 instructions' use of constant operands.
Rename instructions using modified immediate to use suffix
I8M. Many were using I8 which may lead to confusion with
Thumb I8 instructions and some were using other suffixes.
Add and use CmnRI8M, increase constant range of AddRRI12 and
SubRRI12 and use BicRRI8M for applicable kOpAnd constants.
In particular, this should marginaly improve Math.abs(float)
and Math.abs(double) by converting x & 0x7fffffff to BIC.
Bug: 11579369
Change-Id: I0f17a9eb80752d2625730a60555152cdffed50ba
diff --git a/compiler/dex/quick/arm/utility_arm.cc b/compiler/dex/quick/arm/utility_arm.cc
index d631cf7..4819bdf 100644
--- a/compiler/dex/quick/arm/utility_arm.cc
+++ b/compiler/dex/quick/arm/utility_arm.cc
@@ -184,12 +184,12 @@
/* Check Modified immediate special cases */
mod_imm = ModifiedImmediate(value);
if (mod_imm >= 0) {
- res = NewLIR2(kThumb2MovImmShift, r_dest, mod_imm);
+ res = NewLIR2(kThumb2MovI8M, r_dest, mod_imm);
return res;
}
mod_imm = ModifiedImmediate(~value);
if (mod_imm >= 0) {
- res = NewLIR2(kThumb2MvnImm12, r_dest, mod_imm);
+ res = NewLIR2(kThumb2MvnI8M, r_dest, mod_imm);
return res;
}
/* 16-bit immediate? */
@@ -446,7 +446,6 @@
ArmOpcode alt_opcode = kThumbBkpt;
bool all_low_regs = (ARM_LOWREG(r_dest) && ARM_LOWREG(r_src1));
int32_t mod_imm = ModifiedImmediate(value);
- int32_t mod_imm_neg = ModifiedImmediate(-value);
switch (op) {
case kOpLsl:
@@ -482,47 +481,55 @@
else
opcode = (neg) ? kThumbAddRRI3 : kThumbSubRRI3;
return NewLIR3(opcode, r_dest, r_src1, abs_value);
- } else if ((abs_value & 0xff) == abs_value) {
+ } else if ((abs_value & 0x3ff) == abs_value) {
if (op == kOpAdd)
opcode = (neg) ? kThumb2SubRRI12 : kThumb2AddRRI12;
else
opcode = (neg) ? kThumb2AddRRI12 : kThumb2SubRRI12;
return NewLIR3(opcode, r_dest, r_src1, abs_value);
}
- if (mod_imm_neg >= 0) {
- op = (op == kOpAdd) ? kOpSub : kOpAdd;
- mod_imm = mod_imm_neg;
+ if (mod_imm < 0) {
+ mod_imm = ModifiedImmediate(-value);
+ if (mod_imm >= 0) {
+ op = (op == kOpAdd) ? kOpSub : kOpAdd;
+ }
}
if (op == kOpSub) {
- opcode = kThumb2SubRRI8;
+ opcode = kThumb2SubRRI8M;
alt_opcode = kThumb2SubRRR;
} else {
- opcode = kThumb2AddRRI8;
+ opcode = kThumb2AddRRI8M;
alt_opcode = kThumb2AddRRR;
}
break;
case kOpRsub:
- opcode = kThumb2RsubRRI8;
+ opcode = kThumb2RsubRRI8M;
alt_opcode = kThumb2RsubRRR;
break;
case kOpAdc:
- opcode = kThumb2AdcRRI8;
+ opcode = kThumb2AdcRRI8M;
alt_opcode = kThumb2AdcRRR;
break;
case kOpSbc:
- opcode = kThumb2SbcRRI8;
+ opcode = kThumb2SbcRRI8M;
alt_opcode = kThumb2SbcRRR;
break;
case kOpOr:
- opcode = kThumb2OrrRRI8;
+ opcode = kThumb2OrrRRI8M;
alt_opcode = kThumb2OrrRRR;
break;
case kOpAnd:
- opcode = kThumb2AndRRI8;
+ if (mod_imm < 0) {
+ mod_imm = ModifiedImmediate(~value);
+ if (mod_imm >= 0) {
+ return NewLIR3(kThumb2BicRRI8M, r_dest, r_src1, mod_imm);
+ }
+ }
+ opcode = kThumb2AndRRI8M;
alt_opcode = kThumb2AndRRR;
break;
case kOpXor:
- opcode = kThumb2EorRRI8;
+ opcode = kThumb2EorRRI8M;
alt_opcode = kThumb2EorRRR;
break;
case kOpMul:
@@ -531,15 +538,19 @@
alt_opcode = kThumb2MulRRR;
break;
case kOpCmp: {
- int mod_imm = ModifiedImmediate(value);
LIR* res;
if (mod_imm >= 0) {
- res = NewLIR2(kThumb2CmpRI12, r_src1, mod_imm);
+ res = NewLIR2(kThumb2CmpRI8M, r_src1, mod_imm);
} else {
- int r_tmp = AllocTemp();
- res = LoadConstant(r_tmp, value);
- OpRegReg(kOpCmp, r_src1, r_tmp);
- FreeTemp(r_tmp);
+ mod_imm = ModifiedImmediate(-value);
+ if (mod_imm >= 0) {
+ res = NewLIR2(kThumb2CmnRI8M, r_src1, mod_imm);
+ } else {
+ int r_tmp = AllocTemp();
+ res = LoadConstant(r_tmp, value);
+ OpRegReg(kOpCmp, r_src1, r_tmp);
+ FreeTemp(r_tmp);
+ }
}
return res;
}