From 4f206ac1ea1b20400fa242f2f3be86237c4ba3bf Mon Sep 17 00:00:00 2001 From: Nihal Jere Date: Sat, 27 Apr 2024 14:47:15 -0700 Subject: Implement variable length arrays Variably modified types are required for C23. Since QBE doesn't currently support saving and restoring the stack pointer, a current limitation is that we can't reclaim stack space from VLAs that go out of scope. This is potentially problematic for VLAs appearing in a loop, but this case is uncommon enough that it is silently ignored for now. Implements: https://todo.sr.ht/~mcf/cproc/1 References: https://todo.sr.ht/~mcf/cproc/88 Co-authored-by: Michael Forney --- test/func-vla.qbe | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 test/func-vla.qbe (limited to 'test/func-vla.qbe') diff --git a/test/func-vla.qbe b/test/func-vla.qbe new file mode 100644 index 0000000..ac3cb9b --- /dev/null +++ b/test/func-vla.qbe @@ -0,0 +1,24 @@ +export +function w $f(w %.1, l %.3) { +@start.1 + %.2 =l alloc4 4 + storew %.1, %.2 + %.4 =w loadw %.2 + %.5 =l extsw %.4 + %.6 =l mul %.5, 8 + %.7 =l alloc8 8 + storel %.3, %.7 +@body.2 + %.8 =l loadl %.7 + ret %.6 +} +export +function w $main() { +@start.3 + %.1 =l alloc8 40 +@body.4 + %.2 =w call $f(w 5, l %.1) + %.3 =l extsw %.2 + %.4 =w cnel %.3, 40 + ret %.4 +} -- cgit v1.2.3