[jit] Return NULL on zero sized localloc. Fixes coreclr test.

diff --git a/mono/mini/method-to-ir.c b/mono/mini/method-to-ir.c
index d27182afb317ae292ddadc948a9af105db926da4..71878bcf19e54b300e9b068558a03bf0efc60c8c 100644 (file)
--- a/mono/mini/method-to-ir.c
+++ b/mono/mini/method-to-ir.c
@@ -13229,8 +13229,10 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
                                ip += 4;
                                inline_costs += 1;
                                break;
-                       case CEE_LOCALLOC:
+                       case CEE_LOCALLOC: {
                                CHECK_STACK (1);
+                               MonoBasicBlock *non_zero_bb, *end_bb;
+                               int alloc_ptr = alloc_preg (cfg);
                                --sp;
                                if (sp != stack_start) 
                                        UNVERIFIED;
@@ -13242,8 +13244,20 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
                                         */
                                        INLINE_FAILURE("localloc");
 
+                               NEW_BBLOCK (cfg, non_zero_bb);
+                               NEW_BBLOCK (cfg, end_bb);
+
+                               /* if size != zero */
+                               MONO_EMIT_NEW_BIALU_IMM (cfg, OP_COMPARE_IMM, -1, sp [0]->dreg, 0);
+                               MONO_EMIT_NEW_BRANCH_BLOCK (cfg, OP_PBNE_UN, non_zero_bb);
+
+                               //size is zero, so result is NULL
+                               MONO_EMIT_NEW_PCONST (cfg, alloc_ptr, NULL);
+                               MONO_EMIT_NEW_BRANCH_BLOCK (cfg, OP_BR, end_bb);
+
+                               MONO_START_BB (cfg, non_zero_bb);
                                MONO_INST_NEW (cfg, ins, OP_LOCALLOC);
-                               ins->dreg = alloc_preg (cfg);
+                               ins->dreg = alloc_ptr;
                                ins->sreg1 = sp [0]->dreg;
                                ins->type = STACK_PTR;
                                MONO_ADD_INS (cfg->cbb, ins);
@@ -13252,9 +13266,14 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
                                if (init_locals)
                                        ins->flags |= MONO_INST_INIT;
 
+                               MONO_START_BB (cfg, end_bb);
+                               EMIT_NEW_UNALU (cfg, ins, OP_MOVE, alloc_preg (cfg), alloc_ptr);
+                               ins->type = STACK_PTR;
+
                                *sp++ = ins;
                                ip += 2;
                                break;
+                       }
                        case CEE_ENDFILTER: {
                                MonoExceptionClause *clause, *nearest;
                                int cc;