From d90fbe3a0ab69e9a01d68e1f93bf37dec242e72e Mon Sep 17 00:00:00 2001
From: monojenkins <jo.shields+jenkins@xamarin.com>
Date: Tue, 30 Oct 2018 11:13:29 -0400
Subject: [PATCH] [llvm] Fix passing vtypes received by value as arguments,
 they need to be copied. Fixes https://github.com/mono/mono/issues/11378.
 (#11429)

---
 mono/mini/mini-llvm.c | 11 +++++++++--
 mono/mini/objects.cs  | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/mono/mini/mini-llvm.c b/mono/mini/mini-llvm.c
index 9deed7a2cad2..18a9210f949e 100644
--- a/mono/mini/mini-llvm.c
+++ b/mono/mini/mini-llvm.c
@@ -5917,8 +5917,15 @@ process_bb (EmitContext *ctx, MonoBasicBlock *bb)
 					addresses [ins->sreg1] = build_alloca (ctx, t);
 					g_assert (values [ins->sreg1]);
 					LLVMBuildStore (builder, convert (ctx, values [ins->sreg1], type_to_llvm_type (ctx, t)), addresses [ins->sreg1]);
+					addresses [ins->dreg] = addresses [ins->sreg1];
+				} else if (values [ins->sreg1] == addresses [ins->sreg1]) {
+					/* LLVMArgVtypeByRef, have to make a copy */
+					addresses [ins->dreg] = build_alloca (ctx, t);
+					LLVMValueRef v = LLVMBuildLoad (builder, addresses [ins->sreg1], "");
+					LLVMBuildStore (builder, convert (ctx, v, type_to_llvm_type (ctx, t)), addresses [ins->dreg]);
+				} else {
+					addresses [ins->dreg] = addresses [ins->sreg1];
 				}
-				addresses [ins->dreg] = addresses [ins->sreg1];
 			}
 			break;
 		}
@@ -7195,7 +7202,7 @@ emit_method_inner (EmitContext *ctx)
 			else
 				name = g_strdup_printf ("arg_%d", i);
 		}
-		LLVMSetValueName (values [cfg->args [i + sig->hasthis]->dreg], name);
+		LLVMSetValueName (LLVMGetParam (method, pindex), name);
 		g_free (name);
 		if (ainfo->storage == LLVMArgVtypeByVal)
 			mono_llvm_add_param_attr (LLVMGetParam (method, pindex), LLVM_ATTR_BY_VAL);
diff --git a/mono/mini/objects.cs b/mono/mini/objects.cs
index 33c393f33548..4ad7fb70abd1 100644
--- a/mono/mini/objects.cs
+++ b/mono/mini/objects.cs
@@ -1964,6 +1964,41 @@ class SimpleContainer {
 	public static int test_0_dup_vtype () {
 		return new SimpleContainer ().SetFields ();
 	}
+
+	public struct Vec3 {
+		public int X, Y, Z;
+
+		[MethodImplAttribute (MethodImplOptions.NoInlining)]
+			public Vec3(int x, int y, int z) {
+			X = x;
+			Y = y;
+			Z = z;
+		}
+	}
+
+	[MethodImplAttribute (MethodImplOptions.NoInlining)]
+	public static int gh_11378_inner_1 (Vec3 p1, Vec3 p2) {
+		p1.X -= p2.X;
+		p1.Y -= p2.Y;
+		p1.Z -= p2.Z;
+
+		return (int)p2.Y;
+	}
+
+	[MethodImplAttribute (MethodImplOptions.NoInlining)]
+	public static int gh_11378_inner_2 (Vec3 c, Vec3 pos) {
+		return gh_11378_inner_1 (pos, c);
+	}
+
+	static int gh_11378_inner_3 (Vec3 c) {
+		var c2 = c;
+		return gh_11378_inner_2 (c, c2);
+	}
+
+	public static int test_2_gh_11378 () {
+		return gh_11378_inner_3 (new Vec3(0, 2, -20));
+	}
+
 }
 
 #if __MOBILE__