qbe: Fix bitfield sign extension with types shorter than int

2 files changed, 21 insertions, 0 deletions

diff --git a/test/bitfield-short.c b/test/bitfield-short.c
new file mode 100644
index 0000000..b0be6fd
--- /dev/null
+++ b/test/bitfield-short.c
@@ -0,0 +1,7 @@
+struct {
+	short x : 7;
+} s = {.x = -64};
+
+int main(void) {
+	return s.x > 0;
+}
diff --git a/test/bitfield-short.qbe b/test/bitfield-short.qbe
new file mode 100644
index 0000000..e8bc086
--- /dev/null
+++ b/test/bitfield-short.qbe
@@ -0,0 +1,14 @@
+export data $s = align 2 { b 64, z 1 }
+export
+function w $main() {
+@start.1
+@body.2
+	%.1 =l mul 0, 1
+	%.2 =l add $s, %.1
+	%.3 =w loadsh %.2
+	%.4 =w shl %.3, 25
+	%.5 =w sar %.4, 25
+	%.6 =w extsh %.5
+	%.7 =w csgtw %.6, 0
+	ret %.7
+}