If the user asks for a stack clash probe interval of 64kB, we currently
generate a "stdu rX,-65536(r1)" instruction. That instruction does not
exist (the offset is a 16-bit signed number). If the offset is too big
we should force it into a register and generate a "stdux rX,rY,r1"
instruction, instead.
Bootstrapped and regression checked on powerpc64-linux {-m32,-m64};
committing to trunk.
Segher
2017-10-31 Segher Boessenkool <seg...@kernel.crsahing.org>
PR target/82674
* config/rs6000/rs6000.md (allocate_stack): Force update interval
into a register if it does not fit into an immediate offset field.
---
gcc/config/rs6000/rs6000.md | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 62bd19b..18ebe8f 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -10333,6 +10333,9 @@ (define_expand "allocate_stack"
{
rtx loop_lab, end_loop;
bool rotated = CONST_INT_P (rounded_size);
+ rtx update = GEN_INT (-probe_interval);
+ if (probe_interval > 32768)
+ update = force_reg (Pmode, update);
emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop,
last_addr, rotated);
@@ -10340,13 +10343,11 @@ (define_expand "allocate_stack"
if (Pmode == SImode)
emit_insn (gen_movsi_update_stack (stack_pointer_rtx,
stack_pointer_rtx,
- GEN_INT (-probe_interval),
- chain));
+ update, chain));
else
emit_insn (gen_movdi_di_update_stack (stack_pointer_rtx,
stack_pointer_rtx,
- GEN_INT (-probe_interval),
- chain));
+ update, chain));
emit_stack_clash_protection_probe_loop_end (loop_lab, end_loop,
last_addr, rotated);
}
--
1.8.3.1
