From: Zoltan Varga <vargaz@gmail.com>
Date: Tue, 1 Dec 2015 23:50:31 +0000 (-0500)
Subject: [llvm] Zero extend array indexes when targeting llvm, this seems to work around a... 
X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=commitdiff_plain;h=9d6a8f62fc6d076691f4a48bf7ceca5a287aa860;p=mono.git

[llvm] Zero extend array indexes when targeting llvm, this seems to work around a codegen problem on arm64. Fixes #36263.
---

diff --git a/mono/mini/exceptions.cs b/mono/mini/exceptions.cs
index 0148488dee3..e84abc68b01 100644
--- a/mono/mini/exceptions.cs
+++ b/mono/mini/exceptions.cs
@@ -2816,6 +2816,34 @@ class Tests
 		}
 		return finally_called ? 0 : 1;
 	}
+
+	static int array_len_1 = 1;
+
+	public static int test_0_bounds_check_negative_constant () {
+		try {
+			byte[] arr = new byte [array_len_1];
+			byte b = arr [-1];
+			return 1;
+		} catch {
+		}
+		try {
+			byte[] arr = new byte [array_len_1];
+			arr [-1] = 1;
+			return 2;
+		} catch {
+		}
+		return 0;
+	}
+
+	public static int test_0_string_bounds_check_negative_constant () {
+		try {
+			string s = "A";
+			char c = s [-1];
+			return 1;
+		} catch {
+		}
+		return 0;
+	}
 }
 
 #if !__MOBILE__
diff --git a/mono/mini/method-to-ir.c b/mono/mini/method-to-ir.c
index 26536d45eff..1f7a6299738 100644
--- a/mono/mini/method-to-ir.c
+++ b/mono/mini/method-to-ir.c
@@ -5638,6 +5638,9 @@ emit_array_store (MonoCompile *cfg, MonoClass *klass, MonoInst **sp, gboolean sa
 			int index_reg = sp [1]->dreg;
 			int offset = (mono_class_array_element_size (klass) * sp [1]->inst_c0) + MONO_STRUCT_OFFSET (MonoArray, vector);
 
+			if (SIZEOF_REGISTER == 8 && COMPILE_LLVM (cfg))
+				MONO_EMIT_NEW_UNALU (cfg, OP_ZEXT_I4, index_reg, index_reg);
+
 			if (safety_checks)
 				MONO_EMIT_BOUNDS_CHECK (cfg, array_reg, MonoArray, max_length, index_reg);
 			EMIT_NEW_STORE_MEMBASE_TYPE (cfg, ins, &klass->byval_arg, array_reg, offset, sp [2]->dreg);
@@ -5889,8 +5892,12 @@ mini_emit_inst_for_method (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSign
 			int add_reg = alloc_preg (cfg);
 
 #if SIZEOF_REGISTER == 8
-			/* The array reg is 64 bits but the index reg is only 32 */
-			MONO_EMIT_NEW_UNALU (cfg, OP_SEXT_I4, index_reg, args [1]->dreg);
+			if (COMPILE_LLVM (cfg)) {
+				MONO_EMIT_NEW_UNALU (cfg, OP_ZEXT_I4, index_reg, args [1]->dreg);
+			} else {
+				/* The array reg is 64 bits but the index reg is only 32 */
+				MONO_EMIT_NEW_UNALU (cfg, OP_SEXT_I4, index_reg, args [1]->dreg);
+			}
 #else
 			index_reg = args [1]->dreg;
 #endif	
@@ -11716,6 +11723,9 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
 				int index_reg = sp [1]->dreg;
 				int offset = (mono_class_array_element_size (klass) * sp [1]->inst_c0) + MONO_STRUCT_OFFSET (MonoArray, vector);
 
+				if (SIZEOF_REGISTER == 8 && COMPILE_LLVM (cfg))
+					MONO_EMIT_NEW_UNALU (cfg, OP_ZEXT_I4, index_reg, index_reg);
+
 				MONO_EMIT_BOUNDS_CHECK (cfg, array_reg, MonoArray, max_length, index_reg);
 				EMIT_NEW_LOAD_MEMBASE_TYPE (cfg, ins, &klass->byval_arg, array_reg, offset);
 			} else {