Translation blocks are never big enough to require 32-bit branches.
Signed-off-by: Richard Henderson <r...@twiddle.net>
---
tcg/s390/tcg-target.c | 27 ++++++++++++++++++++++-----
1 files changed, 22 insertions(+), 5 deletions(-)
diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
index 13c4de6..81d5ad3 100644
--- a/tcg/s390/tcg-target.c
+++ b/tcg/s390/tcg-target.c
@@ -33,6 +33,11 @@
do { } while (0)
#endif
+/* ??? The translation blocks produced by TCG are generally small enough to
+ be entirely reachable with a 16-bit displacement. Leaving the option for
+ a 32-bit displacement here Just In Case. */
+#define USE_LONG_BRANCHES 0
+
#define TCG_CT_CONST_32 0x0100
#define TCG_CT_CONST_NEG 0x0200
#define TCG_CT_CONST_ADDI 0x0400
@@ -301,14 +306,22 @@ static uint8_t *tb_ret_addr;
static uint64_t facilities;
static void patch_reloc(uint8_t *code_ptr, int type,
- tcg_target_long value, tcg_target_long addend)
+ tcg_target_long value, tcg_target_long addend)
{
- uint32_t *code_ptr_32 = (uint32_t*)code_ptr;
- tcg_target_long code_ptr_tlong = (tcg_target_long)code_ptr;
+ tcg_target_long code_ptr_tl = (tcg_target_long)code_ptr;
+ tcg_target_long pcrel2;
+ /* ??? Not the usual definition of "addend". */
+ pcrel2 = (value - (code_ptr_tl + addend)) >> 1;
+
switch (type) {
+ case R_390_PC16DBL:
+ assert(pcrel2 == (int16_t)pcrel2);
+ *(int16_t *)code_ptr = pcrel2;
+ break;
case R_390_PC32DBL:
- *code_ptr_32 = (value - (code_ptr_tlong + addend)) >> 1;
+ assert(pcrel2 == (int32_t)pcrel2);
+ *(int32_t *)code_ptr = pcrel2;
break;
default:
tcg_abort();
@@ -1091,10 +1104,14 @@ static void tgen_branch(TCGContext *s, int cc, int
labelno)
TCGLabel* l = &s->labels[labelno];
if (l->has_value) {
tgen_gotoi(s, cc, l->u.value);
- } else {
+ } else if (USE_LONG_BRANCHES) {
tcg_out16(s, RIL_BRCL | (cc << 4));
tcg_out_reloc(s, s->code_ptr, R_390_PC32DBL, labelno, -2);
s->code_ptr += 4;
+ } else {
+ tcg_out16(s, RI_BRC | (cc << 4));
+ tcg_out_reloc(s, s->code_ptr, R_390_PC16DBL, labelno, -2);
+ s->code_ptr += 2;
}
}
--
1.7.0.1
