Enhance GenArrayGet, GenArrayPut for x86
As pointed out by Ian Rogers, the x86 versions didn't optimize
handling of constant index expressions. Added that support,
simplified checking of constant indices, and removed the use of
a temporary register for the 'wide' cases by using x86 scaled
addressing mode.
Change-Id: I82174e4e3674752d00d7c4730496f59d69f5f173
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>
diff --git a/compiler/dex/quick/x86/int_x86.cc b/compiler/dex/quick/x86/int_x86.cc
index 340c74a..8ff9ded 100644
--- a/compiler/dex/quick/x86/int_x86.cc
+++ b/compiler/dex/quick/x86/int_x86.cc
@@ -38,6 +38,20 @@
}
/*
+ * Perform a compare of memory to immediate value
+ */
+LIR* X86Mir2Lir::GenMemImmedCheck(ConditionCode c_code,
+ int base, int offset, int check_value, ThrowKind kind) {
+ LIR* tgt = RawLIR(0, kPseudoThrowTarget, kind,
+ current_dalvik_offset_, base, check_value, 0);
+ NewLIR3(IS_SIMM8(check_value) ? kX86Cmp32MI8 : kX86Cmp32MI, base, offset, check_value);
+ LIR* branch = OpCondBranch(c_code, tgt);
+ // Remember branch target - will process later
+ throw_launchpads_.Insert(tgt);
+ return branch;
+}
+
+/*
* Compare two 64-bit values
* x = y return 0
* x < y return -1
@@ -521,41 +535,49 @@
RegLocation rl_index, RegLocation rl_dest, int scale) {
RegisterClass reg_class = oat_reg_class_by_size(size);
int len_offset = mirror::Array::LengthOffset().Int32Value();
- int data_offset;
RegLocation rl_result;
rl_array = LoadValue(rl_array, kCoreReg);
- rl_index = LoadValue(rl_index, kCoreReg);
+ int data_offset;
if (size == kLong || size == kDouble) {
data_offset = mirror::Array::DataOffset(sizeof(int64_t)).Int32Value();
} else {
data_offset = mirror::Array::DataOffset(sizeof(int32_t)).Int32Value();
}
+ bool constant_index = rl_index.is_const;
+ int32_t constant_index_value = 0;
+ if (!constant_index) {
+ rl_index = LoadValue(rl_index, kCoreReg);
+ } else {
+ constant_index_value = mir_graph_->ConstantValue(rl_index);
+ // If index is constant, just fold it into the data offset
+ data_offset += constant_index_value << scale;
+ // treat as non array below
+ rl_index.low_reg = INVALID_REG;
+ }
+
/* null object? */
GenNullCheck(rl_array.s_reg_low, rl_array.low_reg, opt_flags);
if (!(opt_flags & MIR_IGNORE_RANGE_CHECK)) {
- /* if (rl_index >= [rl_array + len_offset]) goto kThrowArrayBounds */
- GenRegMemCheck(kCondUge, rl_index.low_reg, rl_array.low_reg,
- len_offset, kThrowArrayBounds);
+ if (constant_index) {
+ GenMemImmedCheck(kCondLs, rl_array.low_reg, len_offset,
+ constant_index_value, kThrowConstantArrayBounds);
+ } else {
+ GenRegMemCheck(kCondUge, rl_index.low_reg, rl_array.low_reg,
+ len_offset, kThrowArrayBounds);
+ }
}
+ rl_result = EvalLoc(rl_dest, reg_class, true);
if ((size == kLong) || (size == kDouble)) {
- int reg_addr = AllocTemp();
- OpLea(reg_addr, rl_array.low_reg, rl_index.low_reg, scale, data_offset);
- FreeTemp(rl_array.low_reg);
- FreeTemp(rl_index.low_reg);
- rl_result = EvalLoc(rl_dest, reg_class, true);
- LoadBaseIndexedDisp(reg_addr, INVALID_REG, 0, 0, rl_result.low_reg,
+ LoadBaseIndexedDisp(rl_array.low_reg, rl_index.low_reg, scale, data_offset, rl_result.low_reg,
rl_result.high_reg, size, INVALID_SREG);
StoreValueWide(rl_dest, rl_result);
} else {
- rl_result = EvalLoc(rl_dest, reg_class, true);
-
LoadBaseIndexedDisp(rl_array.low_reg, rl_index.low_reg, scale,
data_offset, rl_result.low_reg, INVALID_REG, size,
INVALID_SREG);
-
StoreValue(rl_dest, rl_result);
}
}
@@ -577,14 +599,29 @@
}
rl_array = LoadValue(rl_array, kCoreReg);
- rl_index = LoadValue(rl_index, kCoreReg);
+ bool constant_index = rl_index.is_const;
+ int32_t constant_index_value = 0;
+ if (!constant_index) {
+ rl_index = LoadValue(rl_index, kCoreReg);
+ } else {
+ // If index is constant, just fold it into the data offset
+ constant_index_value = mir_graph_->ConstantValue(rl_index);
+ data_offset += constant_index_value << scale;
+ // treat as non array below
+ rl_index.low_reg = INVALID_REG;
+ }
/* null object? */
GenNullCheck(rl_array.s_reg_low, rl_array.low_reg, opt_flags);
if (!(opt_flags & MIR_IGNORE_RANGE_CHECK)) {
- /* if (rl_index >= [rl_array + len_offset]) goto kThrowArrayBounds */
- GenRegMemCheck(kCondUge, rl_index.low_reg, rl_array.low_reg, len_offset, kThrowArrayBounds);
+ if (constant_index) {
+ GenMemImmedCheck(kCondLs, rl_array.low_reg, len_offset,
+ constant_index_value, kThrowConstantArrayBounds);
+ } else {
+ GenRegMemCheck(kCondUge, rl_index.low_reg, rl_array.low_reg,
+ len_offset, kThrowArrayBounds);
+ }
}
if ((size == kLong) || (size == kDouble)) {
rl_src = LoadValueWide(rl_src, reg_class);
@@ -603,7 +640,9 @@
}
if (card_mark) {
// Free rl_index if its a temp. Ensures there are 2 free regs for card mark.
- FreeTemp(rl_index.low_reg);
+ if (!constant_index) {
+ FreeTemp(rl_index.low_reg);
+ }
MarkGCCard(rl_src.low_reg, rl_array.low_reg);
}
}