Refine aot exception throw, remove unnecessary labels (#456)

core/iwasm/compilation/aot_compiler.c

@@ -1770,13 +1770,6 @@ build_atomic_rmw:
       if (last_block != func_ctx->got_exception_block)
           LLVMMoveBasicBlockAfter(func_ctx->got_exception_block,
                                   last_block);
-
-      /* Move all other exception blocks before got_exception block */
-      for (i = 0; i < EXCE_NUM; i++) {
-          if (func_ctx->exception_blocks[i])
-              LLVMMoveBasicBlockBefore(func_ctx->exception_blocks[i],
-                                       func_ctx->got_exception_block);
-      }
   }
   return true;
 

core/iwasm/compilation/aot_emit_exception.c

@@ -6,22 +6,6 @@
 #include "aot_emit_exception.h"
 #include "../aot/aot_runtime.h"
 
-static char *exce_block_names[] = {
-    "exce_unreachable",             /* EXCE_UNREACHABLE */
-    "exce_out_of_memory",           /* EXCE_OUT_OF_MEMORY */
-    "exce_out_of_bounds_mem_access",/* EXCE_OUT_OF_BOUNDS_MEMORY_ACCESS */
-    "exce_integer_overflow",        /* EXCE_INTEGER_OVERFLOW */
-    "exce_divide_by_zero",          /* EXCE_INTEGER_DIVIDE_BY_ZERO */
-    "exce_invalid_convert_to_int",  /* EXCE_INVALID_CONVERSION_TO_INTEGER */
-    "exce_invalid_func_type_idx",   /* EXCE_INVALID_FUNCTION_TYPE_INDEX */
-    "exce_invalid_func_idx",        /* EXCE_INVALID_FUNCTION_INDEX */
-    "exce_undefined_element",       /* EXCE_UNDEFINED_ELEMENT */
-    "exce_uninit_element",          /* EXCE_UNINITIALIZED_ELEMENT */
-    "exce_call_unlinked",           /* EXCE_CALL_UNLINKED_IMPORT_FUNC */
-    "exce_native_stack_overflow",   /* EXCE_NATIVE_STACK_OVERFLOW */
-    "exce_unaligned_atomic"         /* EXCE_UNALIGNED_ATOMIC */
-};
-
 bool
 aot_emit_exception(AOTCompContext *comp_ctx, AOTFuncContext *func_ctx,
                    int32 exception_id,
@@ -29,7 +13,6 @@ aot_emit_exception(AOTCompContext *comp_ctx, AOTFuncContext *func_ctx,
                    LLVMValueRef cond_br_if,
                    LLVMBasicBlockRef cond_br_else_block)
 {
-    LLVMBasicBlockRef exce_block;
     LLVMBasicBlockRef block_curr = LLVMGetInsertBlock(comp_ctx->builder);
     LLVMValueRef exce_id = I32_CONST((uint32)exception_id), func_const, func;
     LLVMTypeRef param_types[2], ret_type, func_type, func_ptr_type;
@@ -116,36 +99,12 @@ aot_emit_exception(AOTCompContext *comp_ctx, AOTFuncContext *func_ctx,
         LLVMPositionBuilderAtEnd(comp_ctx->builder, block_curr);
     }
 
-    /* Create exception block if needed */
+    /* Add phi incoming value to got_exception block */
-    if (!(exce_block = func_ctx->exception_blocks[exception_id])) {
+    LLVMAddIncoming(func_ctx->exception_id_phi, &exce_id, &block_curr, 1);
-        if (!(func_ctx->exception_blocks[exception_id] = exce_block =
-                LLVMAppendBasicBlockInContext(comp_ctx->context,
-                                              func_ctx->func,
-                                              exce_block_names[exception_id]))) {
-            aot_set_last_error("add LLVM basic block failed.");
-            return false;
-        }
-
-        /* Move before got_exception block */
-        LLVMMoveBasicBlockBefore(exce_block, func_ctx->got_exception_block);
-
-        /* Add phi incoming value to got_exception block */
-        LLVMAddIncoming(func_ctx->exception_id_phi, &exce_id, &exce_block, 1);
-
-        /* Jump to got exception block */
-        LLVMPositionBuilderAtEnd(comp_ctx->builder, exce_block);
-        if (!LLVMBuildBr(comp_ctx->builder, func_ctx->got_exception_block)) {
-            aot_set_last_error("llvm build br failed.");
-            return false;
-        }
-    }
-
-    /* Resume builder position */
-    LLVMPositionBuilderAtEnd(comp_ctx->builder, block_curr);
 
     if (!is_cond_br) {
         /* not condition br, create br IR */
-        if (!LLVMBuildBr(comp_ctx->builder, exce_block)) {
+        if (!LLVMBuildBr(comp_ctx->builder, func_ctx->got_exception_block)) {
             aot_set_last_error("llvm build br failed.");
             return false;
         }
@@ -153,7 +112,7 @@ aot_emit_exception(AOTCompContext *comp_ctx, AOTFuncContext *func_ctx,
     else {
         /* Create condition br */
         if (!LLVMBuildCondBr(comp_ctx->builder, cond_br_if,
-                             exce_block, cond_br_else_block)) {
+                             func_ctx->got_exception_block, cond_br_else_block)) {
             aot_set_last_error("llvm build cond br failed.");
             return false;
         }

core/iwasm/compilation/aot_emit_function.c

@@ -99,7 +99,7 @@ check_call_return(AOTCompContext *comp_ctx, AOTFuncContext *func_ctx,
     /* Add check exection success block */
     if (!(check_call_succ = LLVMAppendBasicBlockInContext(comp_ctx->context,
                                                           func_ctx->func,
-                                                          "check_exce_succ"))) {
+                                                          "check_call_succ"))) {
         aot_set_last_error("llvm add basic block failed.");
         return false;
     }

core/iwasm/compilation/aot_llvm.c

@@ -172,20 +172,6 @@ fail:
     return NULL;
 }
 
-static bool
-create_exception_blocks(AOTFuncContext *func_ctx)
-{
-    if (!(func_ctx->exception_blocks =
-                wasm_runtime_malloc(sizeof(LLVMBasicBlockRef) * EXCE_NUM))) {
-        aot_set_last_error("allocate memory failed.");
-        return false;;
-    }
-
-    memset(func_ctx->exception_blocks, 0,
-           sizeof(LLVMBasicBlockRef) * EXCE_NUM);
-  return true;
-}
-
 static bool
 create_memory_info(AOTCompContext *comp_ctx, AOTFuncContext *func_ctx,
                    LLVMTypeRef int8_ptr_type, uint32 func_index)
@@ -744,10 +730,6 @@ aot_create_func_context(AOTCompData *comp_data, AOTCompContext *comp_ctx,
         goto fail;
     }
 
-    /* Create exception blocks */
-    if (!create_exception_blocks(func_ctx))
-        goto fail;
-
     /* Create base addr, end addr, data size of mem, heap */
     if (!create_memory_info(comp_ctx, func_ctx, int8_ptr_type, func_index))
         goto fail;
@@ -769,8 +751,6 @@ aot_create_func_context(AOTCompData *comp_data, AOTCompContext *comp_ctx,
 fail:
     if (func_ctx->mem_info)
         wasm_runtime_free(func_ctx->mem_info);
-    if (func_ctx->exception_blocks)
-        wasm_runtime_free(func_ctx->exception_blocks);
     aot_block_stack_destroy(&func_ctx->block_stack);
     wasm_runtime_free(func_ctx);
     return NULL;
@@ -785,8 +765,6 @@ aot_destroy_func_contexts(AOTFuncContext **func_ctxes, uint32 count)
         if (func_ctxes[i]) {
             if (func_ctxes[i]->mem_info)
                 wasm_runtime_free(func_ctxes[i]->mem_info);
-            if (func_ctxes[i]->exception_blocks)
-                wasm_runtime_free(func_ctxes[i]->exception_blocks);
             aot_block_stack_destroy(&func_ctxes[i]->block_stack);
             aot_checked_addr_list_destroy(func_ctxes[i]);
             wasm_runtime_free(func_ctxes[i]);