Compiler: Take advantage of constant propagation
The common frontend tracks constants via a constant propagation pass.
When converting from MIR to GBC (for Portable) or LIR (for Quick),
recognize constant arguments and select more efficient codegen forms.
Note: we still have to flush constants to their associated vregs to
support deoptimization. There's quite a bit of possible code size
gain if we were to eliminate unnecessary stores or enhance the vmap
table to explicitly represent the ranges over which Dalvik vregs
are constant.
Also some minor code refactoring related to array operations. There
are sufficient architectural differences to make it worthwhile to
have target-dependent aget/aput generators. On Arm, this is mostly
beneficial to floating point array loads and stores.
This CL yields a ~0.8% decrease in code size over the framework,
and a nice pop to a few of the standard point benchmarks
(linpack: ~10%, cm: ~11%, scimark: ~13% - no significant change to
the others)
Change-Id: I2337e1aa0622b34a34c3775f8b7dbf5e6969da3e
diff --git a/src/compiler/codegen/mips/int_mips.cc b/src/compiler/codegen/mips/int_mips.cc
index bb36dc1..e2a5a02 100644
--- a/src/compiler/codegen/mips/int_mips.cc
+++ b/src/compiler/codegen/mips/int_mips.cc
@@ -432,4 +432,207 @@
return false;
}
+/*
+ * Generate array load
+ */
+void MipsCodegen::GenArrayGet(CompilationUnit* cu, int opt_flags, OpSize size, RegLocation rl_array,
+ RegLocation rl_index, RegLocation rl_dest, int scale)
+{
+ RegisterClass reg_class = oat_reg_class_by_size(size);
+ int len_offset = Array::LengthOffset().Int32Value();
+ int data_offset;
+ RegLocation rl_result;
+ rl_array = LoadValue(cu, rl_array, kCoreReg);
+ rl_index = LoadValue(cu, rl_index, kCoreReg);
+
+ if (size == kLong || size == kDouble) {
+ data_offset = Array::DataOffset(sizeof(int64_t)).Int32Value();
+ } else {
+ data_offset = Array::DataOffset(sizeof(int32_t)).Int32Value();
+ }
+
+ /* null object? */
+ GenNullCheck(cu, rl_array.s_reg_low, rl_array.low_reg, opt_flags);
+
+ int reg_ptr = AllocTemp(cu);
+ bool needs_range_check = (!(opt_flags & MIR_IGNORE_RANGE_CHECK));
+ int reg_len = INVALID_REG;
+ if (needs_range_check) {
+ reg_len = AllocTemp(cu);
+ /* Get len */
+ LoadWordDisp(cu, rl_array.low_reg, len_offset, reg_len);
+ }
+ /* reg_ptr -> array data */
+ OpRegRegImm(cu, kOpAdd, reg_ptr, rl_array.low_reg, data_offset);
+ FreeTemp(cu, rl_array.low_reg);
+ if ((size == kLong) || (size == kDouble)) {
+ if (scale) {
+ int r_new_index = AllocTemp(cu);
+ OpRegRegImm(cu, kOpLsl, r_new_index, rl_index.low_reg, scale);
+ OpRegReg(cu, kOpAdd, reg_ptr, r_new_index);
+ FreeTemp(cu, r_new_index);
+ } else {
+ OpRegReg(cu, kOpAdd, reg_ptr, rl_index.low_reg);
+ }
+ FreeTemp(cu, rl_index.low_reg);
+ rl_result = EvalLoc(cu, rl_dest, reg_class, true);
+
+ if (needs_range_check) {
+ // TODO: change kCondCS to a more meaningful name, is the sense of
+ // carry-set/clear flipped?
+ GenRegRegCheck(cu, kCondCs, rl_index.low_reg, reg_len, kThrowArrayBounds);
+ FreeTemp(cu, reg_len);
+ }
+ LoadBaseDispWide(cu, reg_ptr, 0, rl_result.low_reg, rl_result.high_reg, INVALID_SREG);
+
+ FreeTemp(cu, reg_ptr);
+ StoreValueWide(cu, rl_dest, rl_result);
+ } else {
+ rl_result = EvalLoc(cu, rl_dest, reg_class, true);
+
+ if (needs_range_check) {
+ // TODO: change kCondCS to a more meaningful name, is the sense of
+ // carry-set/clear flipped?
+ GenRegRegCheck(cu, kCondCs, rl_index.low_reg, reg_len, kThrowArrayBounds);
+ FreeTemp(cu, reg_len);
+ }
+ LoadBaseIndexed(cu, reg_ptr, rl_index.low_reg, rl_result.low_reg, scale, size);
+
+ FreeTemp(cu, reg_ptr);
+ StoreValue(cu, rl_dest, rl_result);
+ }
+}
+
+/*
+ * Generate array store
+ *
+ */
+void MipsCodegen::GenArrayPut(CompilationUnit* cu, int opt_flags, OpSize size, RegLocation rl_array,
+ RegLocation rl_index, RegLocation rl_src, int scale)
+{
+ RegisterClass reg_class = oat_reg_class_by_size(size);
+ int len_offset = Array::LengthOffset().Int32Value();
+ int data_offset;
+
+ if (size == kLong || size == kDouble) {
+ data_offset = Array::DataOffset(sizeof(int64_t)).Int32Value();
+ } else {
+ data_offset = Array::DataOffset(sizeof(int32_t)).Int32Value();
+ }
+
+ rl_array = LoadValue(cu, rl_array, kCoreReg);
+ rl_index = LoadValue(cu, rl_index, kCoreReg);
+ int reg_ptr = INVALID_REG;
+ if (IsTemp(cu, rl_array.low_reg)) {
+ Clobber(cu, rl_array.low_reg);
+ reg_ptr = rl_array.low_reg;
+ } else {
+ reg_ptr = AllocTemp(cu);
+ OpRegCopy(cu, reg_ptr, rl_array.low_reg);
+ }
+
+ /* null object? */
+ GenNullCheck(cu, rl_array.s_reg_low, rl_array.low_reg, opt_flags);
+
+ bool needs_range_check = (!(opt_flags & MIR_IGNORE_RANGE_CHECK));
+ int reg_len = INVALID_REG;
+ if (needs_range_check) {
+ reg_len = AllocTemp(cu);
+ //NOTE: max live temps(4) here.
+ /* Get len */
+ LoadWordDisp(cu, rl_array.low_reg, len_offset, reg_len);
+ }
+ /* reg_ptr -> array data */
+ OpRegImm(cu, kOpAdd, reg_ptr, data_offset);
+ /* at this point, reg_ptr points to array, 2 live temps */
+ if ((size == kLong) || (size == kDouble)) {
+ //TUNING: specific wide routine that can handle fp regs
+ if (scale) {
+ int r_new_index = AllocTemp(cu);
+ OpRegRegImm(cu, kOpLsl, r_new_index, rl_index.low_reg, scale);
+ OpRegReg(cu, kOpAdd, reg_ptr, r_new_index);
+ FreeTemp(cu, r_new_index);
+ } else {
+ OpRegReg(cu, kOpAdd, reg_ptr, rl_index.low_reg);
+ }
+ rl_src = LoadValueWide(cu, rl_src, reg_class);
+
+ if (needs_range_check) {
+ GenRegRegCheck(cu, kCondCs, rl_index.low_reg, reg_len, kThrowArrayBounds);
+ FreeTemp(cu, reg_len);
+ }
+
+ StoreBaseDispWide(cu, reg_ptr, 0, rl_src.low_reg, rl_src.high_reg);
+
+ FreeTemp(cu, reg_ptr);
+ } else {
+ rl_src = LoadValue(cu, rl_src, reg_class);
+ if (needs_range_check) {
+ GenRegRegCheck(cu, kCondCs, rl_index.low_reg, reg_len, kThrowArrayBounds);
+ FreeTemp(cu, reg_len);
+ }
+ StoreBaseIndexed(cu, reg_ptr, rl_index.low_reg, rl_src.low_reg,
+ scale, size);
+ }
+}
+
+/*
+ * Generate array store
+ *
+ */
+void MipsCodegen::GenArrayObjPut(CompilationUnit* cu, int opt_flags, RegLocation rl_array,
+ RegLocation rl_index, RegLocation rl_src, int scale)
+{
+ int len_offset = Array::LengthOffset().Int32Value();
+ int data_offset = Array::DataOffset(sizeof(Object*)).Int32Value();
+
+ FlushAllRegs(cu); // Use explicit registers
+ LockCallTemps(cu);
+
+ int r_value = TargetReg(kArg0); // Register holding value
+ int r_array_class = TargetReg(kArg1); // Register holding array's Class
+ int r_array = TargetReg(kArg2); // Register holding array
+ int r_index = TargetReg(kArg3); // Register holding index into array
+
+ LoadValueDirectFixed(cu, rl_array, r_array); // Grab array
+ LoadValueDirectFixed(cu, rl_src, r_value); // Grab value
+ LoadValueDirectFixed(cu, rl_index, r_index); // Grab index
+
+ GenNullCheck(cu, rl_array.s_reg_low, r_array, opt_flags); // NPE?
+
+ // Store of null?
+ LIR* null_value_check = OpCmpImmBranch(cu, kCondEq, r_value, 0, NULL);
+
+ // Get the array's class.
+ LoadWordDisp(cu, r_array, Object::ClassOffset().Int32Value(), r_array_class);
+ CallRuntimeHelperRegReg(cu, ENTRYPOINT_OFFSET(pCanPutArrayElementFromCode), r_value,
+ r_array_class, true);
+ // Redo LoadValues in case they didn't survive the call.
+ LoadValueDirectFixed(cu, rl_array, r_array); // Reload array
+ LoadValueDirectFixed(cu, rl_index, r_index); // Reload index
+ LoadValueDirectFixed(cu, rl_src, r_value); // Reload value
+ r_array_class = INVALID_REG;
+
+ // Branch here if value to be stored == null
+ LIR* target = NewLIR0(cu, kPseudoTargetLabel);
+ null_value_check->target = target;
+
+ bool needs_range_check = (!(opt_flags & MIR_IGNORE_RANGE_CHECK));
+ int reg_len = INVALID_REG;
+ if (needs_range_check) {
+ reg_len = TargetReg(kArg1);
+ LoadWordDisp(cu, r_array, len_offset, reg_len); // Get len
+ }
+ /* r_ptr -> array data */
+ int r_ptr = AllocTemp(cu);
+ OpRegRegImm(cu, kOpAdd, r_ptr, r_array, data_offset);
+ if (needs_range_check) {
+ GenRegRegCheck(cu, kCondCs, r_index, reg_len, kThrowArrayBounds);
+ }
+ StoreBaseIndexed(cu, r_ptr, r_index, r_value, scale, kWord);
+ FreeTemp(cu, r_ptr);
+ FreeTemp(cu, r_index);
+ MarkGCCard(cu, r_value, r_array);
+}
+
} // namespace art