reset register state during ra, not at ir creation time

src/jit/backend/x64/x64_backend.cc

@@ -93,12 +93,10 @@ const struct jit_register x64_registers[] = {
 const int x64_num_registers = ARRAY_SIZE(x64_registers);
 /* clang-format on */
 
-const Xbyak::Reg x64_backend_reg(struct x64_backend *backend,
-                                 const struct ir_value *v) {
-  int i = v->reg;
-  CHECK_NE(i, NO_REGISTER);
-
-  Xbyak::Reg reg = *(const Xbyak::Reg *)x64_registers[i].data;
+Xbyak::Reg x64_backend_reg(struct x64_backend *backend,
+                           const struct ir_value *v) {
+  CHECK(v->reg >= 0 && v->reg < x64_num_registers);
+  Xbyak::Reg reg = *(const Xbyak::Reg *)x64_registers[v->reg].data;
   CHECK(reg.isREG());
 
   switch (v->type) {
@@ -122,12 +120,10 @@ const Xbyak::Reg x64_backend_reg(struct x64_backend *backend,
   return reg;
 }
 
-const Xbyak::Xmm x64_backend_xmm(struct x64_backend *backend,
-                                 const struct ir_value *v) {
-  int i = v->reg;
-  CHECK_NE(i, NO_REGISTER);
-
-  const Xbyak::Xmm &xmm = *(const Xbyak::Xmm *)x64_registers[i].data;
+Xbyak::Xmm x64_backend_xmm(struct x64_backend *backend,
+                           const struct ir_value *v) {
+  CHECK(v->reg >= 0 && v->reg < x64_num_registers);
+  Xbyak::Xmm xmm = *(const Xbyak::Xmm *)x64_registers[v->reg].data;
   CHECK(xmm.isXMM());
   return xmm;
 }

src/jit/backend/x64/x64_local.h

@@ -73,10 +73,10 @@ extern const Xbyak::Reg64 tmp1;
 extern const Xbyak::Reg64 guestctx;
 extern const Xbyak::Reg64 guestmem;
 
-const Xbyak::Reg x64_backend_reg(struct x64_backend *backend,
-                                 const struct ir_value *v);
-const Xbyak::Xmm x64_backend_xmm(struct x64_backend *backend,
-                                 const struct ir_value *v);
+Xbyak::Reg x64_backend_reg(struct x64_backend *backend,
+                           const struct ir_value *v);
+Xbyak::Xmm x64_backend_xmm(struct x64_backend *backend,
+                           const struct ir_value *v);
 void x64_backend_load_mem(struct x64_backend *backend,
                           const struct ir_value *dst,
                           const Xbyak::RegExp &src_exp);

src/jit/ir/ir.c

@@ -160,7 +160,6 @@ struct ir_instr *ir_append_instr(struct ir *ir, enum ir_op op,
     struct ir_value *result = ir_calloc(ir, sizeof(struct ir_value));
     result->type = result_type;
     result->def = instr;
-    result->reg = NO_REGISTER;
     instr->result = result;
   }
 
@@ -222,7 +221,6 @@ struct ir_value *ir_alloc_int(struct ir *ir, int64_t c, enum ir_type type) {
       LOG_FATAL("unexpected value type");
       break;
   }
-  v->reg = NO_REGISTER;
   return v;
 }
 
@@ -230,7 +228,6 @@ struct ir_value *ir_alloc_i8(struct ir *ir, int8_t c) {
   struct ir_value *v = ir_calloc(ir, sizeof(struct ir_value));
   v->type = VALUE_I8;
   v->i8 = c;
-  v->reg = NO_REGISTER;
   return v;
 }
 
@@ -238,7 +235,6 @@ struct ir_value *ir_alloc_i16(struct ir *ir, int16_t c) {
   struct ir_value *v = ir_calloc(ir, sizeof(struct ir_value));
   v->type = VALUE_I16;
   v->i16 = c;
-  v->reg = NO_REGISTER;
   return v;
 }
 
@@ -246,7 +242,6 @@ struct ir_value *ir_alloc_i32(struct ir *ir, int32_t c) {
   struct ir_value *v = ir_calloc(ir, sizeof(struct ir_value));
   v->type = VALUE_I32;
   v->i32 = c;
-  v->reg = NO_REGISTER;
   return v;
 }
 
@@ -254,7 +249,6 @@ struct ir_value *ir_alloc_i64(struct ir *ir, int64_t c) {
   struct ir_value *v = ir_calloc(ir, sizeof(struct ir_value));
   v->type = VALUE_I64;
   v->i64 = c;
-  v->reg = NO_REGISTER;
   return v;
 }
 
@@ -262,7 +256,6 @@ struct ir_value *ir_alloc_f32(struct ir *ir, float c) {
   struct ir_value *v = ir_calloc(ir, sizeof(struct ir_value));
   v->type = VALUE_F32;
   v->f32 = c;
-  v->reg = NO_REGISTER;
   return v;
 }
 
@@ -270,7 +263,6 @@ struct ir_value *ir_alloc_f64(struct ir *ir, double c) {
   struct ir_value *v = ir_calloc(ir, sizeof(struct ir_value));
   v->type = VALUE_F64;
   v->f64 = c;
-  v->reg = NO_REGISTER;
   return v;
 }
 
@@ -282,7 +274,6 @@ struct ir_value *ir_alloc_block_ref(struct ir *ir, struct ir_block *block) {
   struct ir_value *v = ir_calloc(ir, sizeof(struct ir_value));
   v->type = VALUE_BLOCK;
   v->blk = block;
-  v->reg = NO_REGISTER;
   return v;
 }
 

src/jit/ir/ir.h

@@ -7,7 +7,6 @@
 #include "core/list.h"
 
 #define IR_MAX_ARGS 4
-#define NO_REGISTER -1
 
 enum ir_op {
 #define IR_OP(name, flags) OP_##name,

src/jit/passes/register_allocation_pass.c

@@ -73,6 +73,7 @@ struct ra {
   int max_uses;
 };
 
+#define NO_REGISTER -1
 #define NO_TMP -1
 #define NO_USE -1
 
@@ -646,7 +647,8 @@ static void ra_legalize_args(struct ra *ra, struct ir *ir,
   }
 }
 
-static void ra_reset(struct ra *ra, struct ir *ir) {
+static void ra_reset(struct ra *ra, struct ir *ir, struct ir_block *block) {
+  /* reset allocation state */
   for (int i = 0; i < ra->num_registers; i++) {
     struct ra_bin *bin = &ra->bins[i];
     bin->tmp_idx = NO_TMP;
@@ -654,17 +656,22 @@ static void ra_reset(struct ra *ra, struct ir *ir) {
 
   ra->num_tmps = 0;
   ra->num_uses = 0;
+
+  /* reset register state */
+  list_for_each_entry(instr, &block->instrs, struct ir_instr, it) {
+    if (instr->result) {
+      instr->result->reg = NO_REGISTER;
+    }
+  }
 }
 
 void ra_run(struct ra *ra, struct ir *ir) {
   list_for_each_entry(block, &ir->blocks, struct ir_block, it) {
-    ra_reset(ra, ir);
-
+    ra_reset(ra, ir, block);
     ra_legalize_args(ra, ir, block);
     ra_assign_ordinals(ra, ir, block);
     ra_create_tmps(ra, ir, block);
     ra_alloc_bins(ra, ir, block);
-
 #if 1
     ra_validate(ra, ir, block);
 #endif