1 files changed, 39 insertions, 0 deletions
diff --git a/tests/fixtures/call.s b/tests/fixtures/call.s
new file mode 100644
index 0000000..bfc9965
--- /dev/null
+++ b/tests/fixtures/call.s
@@ -0,0 +1,39 @@
+; Build/run from examples/:
+;   ../utils/mcpu-as -o call.o call.s
+;   ../utils/mcpu-ld --stack-size=128 -o call call.o
+;   ../utils/mcpu-run --int-reg=r64@0x00010 call
+;
+; Expected output: 33
+;
+; LibCPU CALL ABI example.
+;
+; add2(a,b): this two-r64 argument block is exactly 16 bytes, so the
+; traditional right-to-left PUSH sequence also satisfies the formal ABI.
+; CALL then pushes
+; the 64-bit return PC, therefore on callee entry:
+;   SP+0  = return address
+;   SP+8  = first argument a
+;   SP+16 = second argument b
+;
+; Before CALL, SP is 16-byte aligned.  The r64 result is returned in the canonical ABI return view
+; r64@0x7fff8.  The caller removes its own arguments with ADJSP.
+
+.text
+_start_life:
+
+        LDI     r64@0x00000, 11
+        LDI     r64@0x00008, 22
+
+        PUSH    r64@0x00008             ; second/rightmost argument b
+        PUSH    r64@0x00000             ; first/leftmost argument a
+        CALL    add2
+        ADJSP   16                       ; caller cleanup
+
+        MOV     r64@0x00010, r64@0x7fff8
+        HALT
+
+add2:
+        LDSP    r64@0x00100, 8           ; a
+        LDSP    r64@0x00108, 16          ; b
+        IADD    r64@0x7fff8, r64@0x00100, r64@0x00108
+        RET