winabi: fix allocation of parameters to regs with hidden argwinabi

In the presence of the hidden arg for return-by-value, the
registers used for natural arguments were incorrect.

(This should be applied on the 'winabi' branch.)

1 files changed, 20 insertions, 0 deletions

diff --git a/test/abi9.ssa b/test/abi9.ssa
new file mode 100644
index 0000000..cb70028
--- /dev/null
+++ b/test/abi9.ssa
@@ -0,0 +1,20 @@
+type :obj = { l, l, l, l }
+
+export
+function :obj $f(l %self) {
+@_0
+        %_1 =l alloc8 16
+	storel 77, %_1
+        ret %_1
+}
+
+# >>> driver
+# #include <stdio.h>
+# typedef struct { long long a, b, c, d; } obj;
+# extern obj f();
+# int main() { obj ret = f(); printf("%lld\n", ret.a); return 0; }
+# <<<
+
+# >>> output
+# 77
+# <<<