Index: src/invocation/apple-call-x86_64.S
==================================================================
--- src/invocation/apple-call-x86_64.S
+++ src/invocation/apple-call-x86_64.S
@@ -23,10 +23,12 @@
 	pushq	%rbp
 	movq	%rsp, %rbp
 
 	subq	$16, %rsp
 	movq	%rdi, -8(%rbp)
+
+	movb	177(%rdi), %al
 
 	movdqa	176(%rdi), %xmm7
 	movdqa	160(%rdi), %xmm6
 	movdqa	144(%rdi), %xmm5
 	movdqa	128(%rdi), %xmm4

Index: src/invocation/invoke-x86_64.m
==================================================================
--- src/invocation/invoke-x86_64.m
+++ src/invocation/invoke-x86_64.m
@@ -30,10 +30,11 @@
 #define NUM_SSE_OUT 2
 
 struct registers {
 	uint64_t gpr[NUM_GPR_IN + NUM_GPR_OUT];
 	__m128 sse[NUM_SSE_IN];
+	uint8_t num_sse;
 };
 
 extern void of_invocation_call(struct registers *);
 
 void
@@ -42,10 +43,12 @@
 	OFMethodSignature *methodSignature = [invocation methodSignature];
 	size_t numberOfArguments = [methodSignature numberOfArguments];
 	const char *typeEncoding;
 	struct registers registers;
 	size_t currentGPR = 0, currentSSE = 0;
+
+	memset(&registers, '\0', sizeof(registers));
 
 	for (size_t i = 0; i < numberOfArguments; i++) {
 		union {
 			uint64_t gpr;
 			__m128 sse;
@@ -126,13 +129,14 @@
 				registers.gpr[currentGPR++] = value.gpr;
 			else
 				/* TODO */
 				abort();
 		} else if (valueType == VALUE_SSE) {
-			if (currentSSE < NUM_SSE_IN)
+			if (currentSSE < NUM_SSE_IN) {
 				registers.sse[currentSSE++] = value.sse;
-			else
+				registers.num_sse++;
+			} else
 				/* TODO */
 				abort();
 		}
 	}