Rewrite kMirOpSelect for all IF_ccZ opcodes.
Also improve special cases for ARM and add tests.
Change-Id: I06f575b9c7b547dbc431dbfadf2b927151fe16b9
diff --git a/compiler/dex/quick/arm/int_arm.cc b/compiler/dex/quick/arm/int_arm.cc
index 94c8844..fb2096f 100644
--- a/compiler/dex/quick/arm/int_arm.cc
+++ b/compiler/dex/quick/arm/int_arm.cc
@@ -172,19 +172,33 @@
RegLocation rl_src = mir_graph_->GetSrc(mir, 0);
RegLocation rl_dest = mir_graph_->GetDest(mir);
rl_src = LoadValue(rl_src, kCoreReg);
+ ConditionCode ccode = mir->meta.ccode;
if (mir->ssa_rep->num_uses == 1) {
// CONST case
int true_val = mir->dalvikInsn.vB;
int false_val = mir->dalvikInsn.vC;
rl_result = EvalLoc(rl_dest, kCoreReg, true);
- if ((true_val == 1) && (false_val == 0)) {
- OpRegRegImm(kOpRsub, rl_result.reg.GetReg(), rl_src.reg.GetReg(), 1);
- OpIT(kCondUlt, "");
- LoadConstant(rl_result.reg.GetReg(), 0);
+ // Change kCondNe to kCondEq for the special cases below.
+ if (ccode == kCondNe) {
+ ccode = kCondEq;
+ std::swap(true_val, false_val);
+ }
+ bool cheap_false_val = InexpensiveConstantInt(false_val);
+ if (cheap_false_val && ccode == kCondEq && (true_val == 0 || true_val == -1)) {
+ OpRegRegImm(kOpSub, rl_result.reg.GetReg(), rl_src.reg.GetReg(), -true_val);
+ DCHECK(last_lir_insn_->u.m.def_mask & ENCODE_CCODE);
+ OpIT(true_val == 0 ? kCondNe : kCondUge, "");
+ LoadConstant(rl_result.reg.GetReg(), false_val);
GenBarrier(); // Add a scheduling barrier to keep the IT shadow intact
- } else if (InexpensiveConstantInt(true_val) && InexpensiveConstantInt(false_val)) {
+ } else if (cheap_false_val && ccode == kCondEq && true_val == 1) {
+ OpRegRegImm(kOpRsub, rl_result.reg.GetReg(), rl_src.reg.GetReg(), 1);
+ DCHECK(last_lir_insn_->u.m.def_mask & ENCODE_CCODE);
+ OpIT(kCondLs, "");
+ LoadConstant(rl_result.reg.GetReg(), false_val);
+ GenBarrier(); // Add a scheduling barrier to keep the IT shadow intact
+ } else if (cheap_false_val && InexpensiveConstantInt(true_val)) {
OpRegImm(kOpCmp, rl_src.reg.GetReg(), 0);
- OpIT(kCondEq, "E");
+ OpIT(ccode, "E");
LoadConstant(rl_result.reg.GetReg(), true_val);
LoadConstant(rl_result.reg.GetReg(), false_val);
GenBarrier(); // Add a scheduling barrier to keep the IT shadow intact
@@ -195,7 +209,7 @@
LoadConstant(t_reg1, true_val);
LoadConstant(t_reg2, false_val);
OpRegImm(kOpCmp, rl_src.reg.GetReg(), 0);
- OpIT(kCondEq, "E");
+ OpIT(ccode, "E");
OpRegCopy(rl_result.reg.GetReg(), t_reg1);
OpRegCopy(rl_result.reg.GetReg(), t_reg2);
GenBarrier(); // Add a scheduling barrier to keep the IT shadow intact
@@ -209,13 +223,13 @@
rl_result = EvalLoc(rl_dest, kCoreReg, true);
OpRegImm(kOpCmp, rl_src.reg.GetReg(), 0);
if (rl_result.reg.GetReg() == rl_true.reg.GetReg()) { // Is the "true" case already in place?
- OpIT(kCondNe, "");
+ OpIT(NegateComparison(ccode), "");
OpRegCopy(rl_result.reg.GetReg(), rl_false.reg.GetReg());
} else if (rl_result.reg.GetReg() == rl_false.reg.GetReg()) { // False case in place?
- OpIT(kCondEq, "");
+ OpIT(ccode, "");
OpRegCopy(rl_result.reg.GetReg(), rl_true.reg.GetReg());
} else { // Normal - select between the two.
- OpIT(kCondEq, "E");
+ OpIT(ccode, "E");
OpRegCopy(rl_result.reg.GetReg(), rl_true.reg.GetReg());
OpRegCopy(rl_result.reg.GetReg(), rl_false.reg.GetReg());
}
diff --git a/compiler/dex/quick/codegen_util.cc b/compiler/dex/quick/codegen_util.cc
index eb6f9d1..14469b6 100644
--- a/compiler/dex/quick/codegen_util.cc
+++ b/compiler/dex/quick/codegen_util.cc
@@ -967,6 +967,22 @@
return res;
}
+ConditionCode Mir2Lir::NegateComparison(ConditionCode before) {
+ ConditionCode res;
+ switch (before) {
+ case kCondEq: res = kCondNe; break;
+ case kCondNe: res = kCondEq; break;
+ case kCondLt: res = kCondGe; break;
+ case kCondGt: res = kCondLe; break;
+ case kCondLe: res = kCondGt; break;
+ case kCondGe: res = kCondLt; break;
+ default:
+ res = static_cast<ConditionCode>(0);
+ LOG(FATAL) << "Unexpected ccode " << before;
+ }
+ return res;
+}
+
// TODO: move to mir_to_lir.cc
Mir2Lir::Mir2Lir(CompilationUnit* cu, MIRGraph* mir_graph, ArenaAllocator* arena)
: Backend(arena),
diff --git a/compiler/dex/quick/mir_to_lir.h b/compiler/dex/quick/mir_to_lir.h
index 19621b0..9e0e299 100644
--- a/compiler/dex/quick/mir_to_lir.h
+++ b/compiler/dex/quick/mir_to_lir.h
@@ -425,6 +425,7 @@
bool EvaluateBranch(Instruction::Code opcode, int src1, int src2);
bool IsInexpensiveConstant(RegLocation rl_src);
ConditionCode FlipComparisonOrder(ConditionCode before);
+ ConditionCode NegateComparison(ConditionCode before);
virtual void InstallLiteralPools();
void InstallSwitchTables();
void InstallFillArrayData();
diff --git a/compiler/dex/quick/x86/int_x86.cc b/compiler/dex/quick/x86/int_x86.cc
index 5900990..d12c057 100644
--- a/compiler/dex/quick/x86/int_x86.cc
+++ b/compiler/dex/quick/x86/int_x86.cc
@@ -190,6 +190,7 @@
RegLocation rl_src = mir_graph_->GetSrc(mir, 0);
RegLocation rl_dest = mir_graph_->GetDest(mir);
rl_src = LoadValue(rl_src, kCoreReg);
+ ConditionCode ccode = mir->meta.ccode;
// The kMirOpSelect has two variants, one for constants and one for moves.
const bool is_constant_case = (mir->ssa_rep->num_uses == 1);
@@ -200,6 +201,8 @@
rl_result = EvalLoc(rl_dest, kCoreReg, true);
/*
+ * For ccode == kCondEq:
+ *
* 1) When the true case is zero and result_reg is not same as src_reg:
* xor result_reg, result_reg
* cmp $0, src_reg
@@ -212,9 +215,9 @@
* cmovz result_reg, t1
* 3) All other cases (we do compare first to set eflags):
* cmp $0, src_reg
- * mov result_reg, $true_case
- * mov t1, $false_case
- * cmovnz result_reg, t1
+ * mov result_reg, $false_case
+ * mov t1, $true_case
+ * cmovz result_reg, t1
*/
const bool result_reg_same_as_src = (rl_src.location == kLocPhysReg && rl_src.reg.GetReg() == rl_result.reg.GetReg());
const bool true_zero_case = (true_val == 0 && false_val != 0 && !result_reg_same_as_src);
@@ -230,15 +233,15 @@
}
if (catch_all_case) {
- OpRegImm(kOpMov, rl_result.reg.GetReg(), true_val);
+ OpRegImm(kOpMov, rl_result.reg.GetReg(), false_val);
}
if (true_zero_case || false_zero_case || catch_all_case) {
- int immediateForTemp = false_zero_case ? true_val : false_val;
+ ConditionCode cc = true_zero_case ? NegateComparison(ccode) : ccode;
+ int immediateForTemp = true_zero_case ? false_val : true_val;
int temp1_reg = AllocTemp();
OpRegImm(kOpMov, temp1_reg, immediateForTemp);
- ConditionCode cc = false_zero_case ? kCondEq : kCondNe;
OpCondRegReg(kOpCmov, cc, rl_result.reg.GetReg(), temp1_reg);
FreeTemp(temp1_reg);
@@ -251,6 +254,8 @@
rl_result = EvalLoc(rl_dest, kCoreReg, true);
/*
+ * For ccode == kCondEq:
+ *
* 1) When true case is already in place:
* cmp $0, src_reg
* cmovnz result_reg, false_reg
@@ -259,20 +264,20 @@
* cmovz result_reg, true_reg
* 3) When neither cases are in place:
* cmp $0, src_reg
- * mov result_reg, true_reg
- * cmovnz result_reg, false_reg
+ * mov result_reg, false_reg
+ * cmovz result_reg, true_reg
*/
// kMirOpSelect is generated just for conditional cases when comparison is done with zero.
OpRegImm(kOpCmp, rl_src.reg.GetReg(), 0);
if (rl_result.reg.GetReg() == rl_true.reg.GetReg()) {
- OpCondRegReg(kOpCmov, kCondNe, rl_result.reg.GetReg(), rl_false.reg.GetReg());
+ OpCondRegReg(kOpCmov, NegateComparison(ccode), rl_result.reg.GetReg(), rl_false.reg.GetReg());
} else if (rl_result.reg.GetReg() == rl_false.reg.GetReg()) {
- OpCondRegReg(kOpCmov, kCondEq, rl_result.reg.GetReg(), rl_true.reg.GetReg());
+ OpCondRegReg(kOpCmov, ccode, rl_result.reg.GetReg(), rl_true.reg.GetReg());
} else {
- OpRegCopy(rl_result.reg.GetReg(), rl_true.reg.GetReg());
- OpCondRegReg(kOpCmov, kCondNe, rl_result.reg.GetReg(), rl_false.reg.GetReg());
+ OpRegCopy(rl_result.reg.GetReg(), rl_false.reg.GetReg());
+ OpCondRegReg(kOpCmov, ccode, rl_result.reg.GetReg(), rl_true.reg.GetReg());
}
}