From cb947b7a56c09febb89b02b89599c003874b23f3 Mon Sep 17 00:00:00 2001
From: Zoltan Varga <vargaz@gmail.com>
Date: Wed, 22 Feb 2017 15:06:08 -0500
Subject: [PATCH] [arm] Fix the passing of structs with 8 byte alignment with
 llvm on armeabi, they need to be passed as an int64 array to let llvm know
 that it might need to insert a dummy argument so they are passed in a even
 register pair. Fixes #52548.

---
 mono/mini/mini-arm.c  | 12 +++++++++++-
 mono/mini/mini-arm.h  |  2 +-
 mono/mini/mini-llvm.c | 10 ++++++++--
 mono/mini/mini.h      |  2 +-
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/mono/mini/mini-arm.c b/mono/mini/mini-arm.c
index 42715480b00..f85644d42ca 100644
--- a/mono/mini/mini-arm.c
+++ b/mono/mini/mini-arm.c
@@ -1515,6 +1515,7 @@ get_call_info (MonoMemPool *mp, MonoMethodSignature *sig)
 			nwords = (align_size + sizeof (gpointer) -1 ) / sizeof (gpointer);
 			ainfo->storage = RegTypeStructByVal;
 			ainfo->struct_size = size;
+			ainfo->align = align;
 			/* FIXME: align stack_size if needed */
 			if (eabi_supported) {
 				if (align >= 8 && (gr & 1))
@@ -2166,7 +2167,16 @@ mono_arch_get_llvm_call_info (MonoCompile *cfg, MonoMethodSignature *sig)
 			break;
 		case RegTypeStructByVal:
 			lainfo->storage = LLVMArgAsIArgs;
-			lainfo->nslots = ainfo->struct_size / sizeof (gpointer);
+			if (eabi_supported && ainfo->align == 8) {
+				/* LLVM models this by passing an int64 array */
+				lainfo->nslots = ALIGN_TO (ainfo->struct_size, 8) / 8;
+				lainfo->esize = 8;
+			} else {
+				lainfo->nslots = ainfo->struct_size / sizeof (gpointer);
+				lainfo->esize = 4;
+			}
+
+			printf ("D: %d\n", ainfo->align);
 			break;
 		case RegTypeStructByAddr:
 		case RegTypeStructByAddrOnStack:
diff --git a/mono/mini/mini-arm.h b/mono/mini/mini-arm.h
index 28678638b6c..31194f2e60d 100644
--- a/mono/mini/mini-arm.h
+++ b/mono/mini/mini-arm.h
@@ -208,7 +208,7 @@ typedef struct {
 	guint8  reg;
 	ArgStorage  storage;
 	/* RegTypeStructByVal */
-	gint32  struct_size;
+	gint32  struct_size, align;
 	guint8  size    : 4; /* 1, 2, 4, 8, or regs used by RegTypeStructByVal */
 } ArgInfo;
 
diff --git a/mono/mini/mini-llvm.c b/mono/mini/mini-llvm.c
index 563607f8c0f..745c29f13e4 100644
--- a/mono/mini/mini-llvm.c
+++ b/mono/mini/mini-llvm.c
@@ -1431,7 +1431,10 @@ sig_to_llvm_sig_full (EmitContext *ctx, MonoMethodSignature *sig, LLVMCallInfo *
 			pindex ++;
 			break;
 		case LLVMArgAsIArgs:
-			param_types [pindex] = LLVMArrayType (IntPtrType (), ainfo->nslots);
+			if (ainfo->esize == 8)
+				param_types [pindex] = LLVMArrayType (LLVMInt64Type (), ainfo->nslots);
+			else
+				param_types [pindex] = LLVMArrayType (IntPtrType (), ainfo->nslots);
 			pindex ++;
 			break;
 		case LLVMArgVtypeByRef:
@@ -3490,7 +3493,10 @@ process_call (EmitContext *ctx, MonoBasicBlock *bb, LLVMBuilderRef *builder_ref,
 		}
 		case LLVMArgAsIArgs:
 			g_assert (addresses [reg]);
-			args [pindex] = LLVMBuildLoad (ctx->builder, convert (ctx, addresses [reg], LLVMPointerType (LLVMArrayType (IntPtrType (), ainfo->nslots), 0)), "");
+			if (ainfo->esize == 8)
+				args [pindex] = LLVMBuildLoad (ctx->builder, convert (ctx, addresses [reg], LLVMPointerType (LLVMArrayType (LLVMInt64Type (), ainfo->nslots), 0)), "");
+			else
+				args [pindex] = LLVMBuildLoad (ctx->builder, convert (ctx, addresses [reg], LLVMPointerType (LLVMArrayType (IntPtrType (), ainfo->nslots), 0)), "");
 			break;
 		case LLVMArgVtypeAsScalar:
 			g_assert_not_reached ();
diff --git a/mono/mini/mini.h b/mono/mini/mini.h
index 25316da3245..d8e9f9ca547 100644
--- a/mono/mini/mini.h
+++ b/mono/mini/mini.h
@@ -826,7 +826,7 @@ typedef struct {
 	 * in the structure.
 	 */
 	int nslots;
-	/* Only if storage == LLVMArgAsFpArgs/LLVMArgFpStruct (4/8) */
+	/* Only if storage == LLVMArgAsIArgs/LLVMArgAsFpArgs/LLVMArgFpStruct (4/8) */
 	int esize;
 	/* Parameter index in the LLVM signature */
 	int pindex;
-- 
2.25.1