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[Qemu-devel] [PATCH 08/14] tcg-ppc64: Look through a constant function d
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH 08/14] tcg-ppc64: Look through a constant function descriptor |
Date: |
Sun, 1 Sep 2013 09:16:07 -0700 |
Especially in the user-only configurations, a direct branch into
the executable may be in range.
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/ppc64/tcg-target.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
index 033518c..95980ce 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) {
--
1.8.3.1
- [Qemu-devel] [PATCH 00/14] tcg-ppc64 improvements, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 01/14] tcg-ppc64: Reformat tcg-target.c, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 02/14] tcg-ppc64: More use of TAI and SAI helper macros, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 03/14] tcg-ppc64: Use TCG_REG_Rn constants, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 04/14] tcg-ppc64: Use tcg_out64, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 06/14] tcg-ppc64: Don't load the static chain from TCG, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 05/14] tcg-ppc64: Avoid code for nop move, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 07/14] tcg-ppc64: Fold constant call address into descriptor load, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 08/14] tcg-ppc64: Look through a constant function descriptor,
Richard Henderson <=
- [Qemu-devel] [PATCH 09/14] tcg-ppc64: Tidy register allocation order, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 11/14] tcg-ppc64: Implement tcg_register_jit, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 10/14] tcg-ppc64: Handle long offsets better, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 12/14] tcg-ppc64: Streamline tcg_out_tlb_read, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 13/14] tcg-ppc64: Add _noaddr functions for emitting forward branches, Richard Henderson, 2013/09/01
- [Qemu-devel] [PATCH 14/14] tcg-ppc64: Implement CONFIG_QEMU_LDST_OPTIMIZATION, Richard Henderson, 2013/09/01