Am 07.07.2011 14:37, schrieb Kirill Batuzov:
Make tcg_constant_folding do copy and constant propagation. It is a
preparational work before actual constant folding.
Signed-off-by: Kirill Batuzov<batuz...@ispras.ru>
---
tcg/optimize.c | 182 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 180 insertions(+), 2 deletions(-)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index c7c7da9..f8afe71 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
...
This patch breaks QEMU on 32 bit hosts (tested on 386 Linux
and w32 hosts). Simply running qemu (BIOS only) terminates
with abort(). As the error is easy to reproduce, I don't provide
a stack frame here.
+static void tcg_opt_gen_mov(TCGArg *gen_args, TCGArg dst, TCGArg src,
+ int nb_temps, int nb_globals)
+{
+ reset_temp(dst, nb_temps, nb_globals);
+ assert(temps[src].state != TCG_TEMP_COPY);
+ if (src>= nb_globals) {
+ assert(temps[src].state != TCG_TEMP_CONST);
+ if (temps[src].state != TCG_TEMP_HAS_COPY) {
+ temps[src].state = TCG_TEMP_HAS_COPY;
+ temps[src].next_copy = src;
+ temps[src].prev_copy = src;
+ }
+ temps[dst].state = TCG_TEMP_COPY;
+ temps[dst].val = src;
+ temps[dst].next_copy = temps[src].next_copy;
+ temps[dst].prev_copy = src;
+ temps[temps[dst].next_copy].prev_copy = dst;
+ temps[src].next_copy = dst;
+ }
+ gen_args[0] = dst;
+ gen_args[1] = src;
+}
QEMU with a modified tcg_opt_gen_mov() (without the if block) works.
Kind regards,
Stefan Weil
