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authorRichard Henderson <rth@twiddle.net>2013-08-31 06:30:45 -0700
committerRichard Henderson <rth@twiddle.net>2013-09-25 07:46:32 -0700
commitb0940da012c4c80145fdcf1730620f28ce80c2d8 (patch)
tree61f7231c6d50e338f06da07885800c3d7000bc5e /tcg
parentd40f3cb1128208d901b6224b52ff36ff05680d28 (diff)
tcg-ppc64: Look through a constant function descriptor
Especially in the user-only configurations, a direct branch into the executable may be in range. Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg')
-rw-r--r--tcg/ppc64/tcg-target.c23
1 files changed, 19 insertions, 4 deletions
diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
index 8eb04060e6..0659dd6e66 100644
--- a/tcg/ppc64/tcg-target.c
+++ b/tcg/ppc64/tcg-target.c
@@ -173,14 +173,17 @@ static const int tcg_target_callee_save_regs[] = {
TCG_REG_R31
};
+static inline bool in_range_b(tcg_target_long target)
+{
+ return target == sextract64(target, 0, 26);
+}
+
static uint32_t reloc_pc24_val(void *pc, tcg_target_long target)
{
tcg_target_long disp;
disp = target - (tcg_target_long)pc;
- if ((disp << 38) >> 38 != disp) {
- tcg_abort();
- }
+ assert(in_range_b(disp));
return disp & 0x3fffffc;
}
@@ -694,7 +697,7 @@ static void tcg_out_b(TCGContext *s, int mask, tcg_target_long target)
tcg_target_long disp;
disp = target - (tcg_target_long)s->code_ptr;
- if ((disp << 38) >> 38 == disp) {
+ if (in_range_b(disp)) {
tcg_out32(s, B | (disp & 0x3fffffc) | mask);
} else {
tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_R0, (tcg_target_long)target);
@@ -717,6 +720,18 @@ static void tcg_out_call(TCGContext *s, tcg_target_long arg, int const_arg)
int ofs = 0;
if (const_arg) {
+ /* Look through the descriptor. If the branch is in range, and we
+ don't have to spend too much effort on building the toc. */
+ intptr_t tgt = ((intptr_t *)arg)[0];
+ intptr_t toc = ((intptr_t *)arg)[1];
+ intptr_t diff = tgt - (intptr_t)s->code_ptr;
+
+ if (in_range_b(diff) && toc == (uint32_t)toc) {
+ tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_R2, toc);
+ tcg_out_b(s, LK, tgt);
+ return;
+ }
+
/* Fold the low bits of the constant into the addresses below. */
ofs = (int16_t)arg;
if (ofs + 8 < 0x8000) {