LIR skeleton, renaming some types to prevent conflict.

2013-12-29 14:28:46 -08:00
parent 7d83ba0021
commit 3d01efffac
66 changed files with 817 additions and 762 deletions
--- a/src/alloy/compiler/compiler_passes.h
+++ b/src/alloy/compiler/compiler_passes.h
@@ -0,0 +1,136 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2013 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef ALLOY_COMPILER_COMPILER_PASSES_H_
+#define ALLOY_COMPILER_COMPILER_PASSES_H_
+
+#include <alloy/compiler/passes/constant_propagation_pass.h>
+#include <alloy/compiler/passes/context_promotion_pass.h>
+#include <alloy/compiler/passes/dead_code_elimination_pass.h>
+//#include <alloy/compiler/passes/dead_store_elimination_pass.h>
+#include <alloy/compiler/passes/simplification_pass.h>
+
+// TODO:
+//   - mark_use/mark_set
+//     For now: mark_all_changed on all calls
+//     For external functions:
+//       - load_context/mark_use on all arguments
+//       - mark_set on return argument?
+//     For internal functions:
+//       - if liveness analysis already done, use that
+//       - otherwise, assume everything dirty (ACK!)
+//       - could use scanner to insert mark_use
+//
+//   Maybe:
+//   - v0.xx = load_constant <c>
+//   - v0.xx = load_zero
+//   Would prevent NULL defs on values, and make constant de-duping possible.
+//   Not sure if it's worth it, though, as the extra register allocation
+//   pressure due to de-duped constants seems like it would slow things down
+//   a lot.
+//
+//   - CFG:
+//     Blocks need predecessors()/successor()
+//     phi Instr reference
+//
+//   - block liveness tracking (in/out)
+//     Block gets:
+//       AddIncomingValue(Value* value, Block* src_block) ??
+
+
+// Potentially interesting passes:
+//
+// Run order:
+//   ContextPromotion
+//   Simplification
+//   ConstantPropagation
+//   TypePropagation
+//   ByteSwapElimination
+//   Simplification
+//   DeadStoreElimination
+//   DeadCodeElimination
+//
+// - TypePropagation
+//    There are many extensions/truncations in generated code right now due to
+//    various load/stores of varying widths. Being able to find and short-
+//    circuit the conversions early on would make following passes cleaner
+//    and faster as they'd have to trace through fewer value definitions.
+//    Example (after ContextPromotion):
+//      v81.i64 = load_context +88
+//      v82.i32 = truncate v81.i64
+//      v84.i32 = and v82.i32, 3F
+//      v85.i64 = zero_extend v84.i32
+//      v87.i64 = load_context +248
+//      v88.i64 = v85.i64
+//      v89.i32 = truncate v88.i64      <-- zero_extend/truncate => v84.i32
+//      v90.i32 = byte_swap v89.i32
+//      store v87.i64, v90.i32
+//    after type propagation / simplification / DCE:
+//      v81.i64 = load_context +88
+//      v82.i32 = truncate v81.i64
+//      v84.i32 = and v82.i32, 3F
+//      v87.i64 = load_context +248
+//      v90.i32 = byte_swap v84.i32
+//      store v87.i64, v90.i32
+//
+// - ByteSwapElimination
+//   Find chained byte swaps and replace with assignments. This is often found
+//   in memcpy paths.
+//   Example:
+//     v0 = load ...
+//     v1 = byte_swap v0
+//     v2 = byte_swap v1
+//     store ..., v2       <-- this could be v0
+//
+//   It may be tricky to detect, though, as often times there are intervening
+//   instructions:
+//     v21.i32 = load v20.i64
+//     v22.i32 = byte_swap v21.i32
+//     v23.i64 = zero_extend v22.i32
+//     v88.i64 = v23.i64 (from ContextPromotion)
+//     v89.i32 = truncate v88.i64
+//     v90.i32 = byte_swap v89.i32
+//     store v87.i64, v90.i32
+//   After type propagation:
+//     v21.i32 = load v20.i64
+//     v22.i32 = byte_swap v21.i32
+//     v89.i32 = v22.i32
+//     v90.i32 = byte_swap v89.i32
+//     store v87.i64, v90.i32
+//   This could ideally become:
+//     v21.i32 = load v20.i64
+//     ... (DCE takes care of this) ...
+//     store v87.i64, v21.i32
+//
+// - DeadStoreElimination
+//   Generic DSE pass, removing all redundant stores. ContextPromotion may be
+//   able to take care of most of these, as the input assembly is generally
+//   pretty optimized already. This pass would mainly be looking for introduced
+//   stores, such as those from comparisons.
+//
+//   Example:
+//   <block0>:
+//     v0 = compare_ult ...     (later removed by DCE)
+//     v1 = compare_ugt ...     (later removed by DCE)
+//     v2 = compare_eq ...
+//     store_context +300, v0   <-- removed
+//     store_context +301, v1   <-- removed
+//     store_context +302, v2   <-- removed
+//     branch_true v1, ...
+//   <block1>:
+//     v3 = compare_ult ...
+//     v4 = compare_ugt ...
+//     v5 = compare_eq ...
+//     store_context +300, v3   <-- these may be required if at end of function
+//     store_context +301, v4       or before a call
+//     store_context +302, v5
+//     branch_true v5, ...
+//
+
+#endif  // ALLOY_COMPILER_COMPILER_PASSES_H_