From: Manolis Tsamis <manolis.tsa...@vrull.eu>
Fixes: 6a2e8dcbbd4bab3
Propagation for the stack pointer in regcprop was enabled in
6a2e8dcbbd4bab3, but set ORIGINAL_REGNO/REG_ATTRS/REG_POINTER for
stack_pointer_rtx which caused regression (e.g., PR 110313, PR 110308).
This fix adds special handling for stack_pointer_rtx in the places
where maybe_mode_change is called. This also adds an check in
maybe_mode_change to return the stack pointer only when the requested
mode matches the mode of stack_pointer_rtx.
PR 110308
gcc/ChangeLog:
* regcprop.cc (maybe_mode_change): Check stack_pointer_rtx mode.
(find_oldest_value_reg): Special handling of stack_pointer_rtx.
(copyprop_hardreg_forward_1): Ditto.
gcc/testsuite/ChangeLog:
* g++.dg/torture/pr110308.C: New test.
Signed-off-by: Manolis Tsamis <manolis.tsa...@vrull.eu>
Signed-off-by: Philipp Tomsich <philipp.toms...@vrull.eu>
---
This addresses both the PRs (110308 and 110313) and was confirmed to
resolve the AArch64 bootstrap issue reported by Thiago.
OK for trunk?
gcc/regcprop.cc | 43 +++++++++++++++++--------
gcc/testsuite/g++.dg/torture/pr110308.C | 30 +++++++++++++++++
2 files changed, 60 insertions(+), 13 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/torture/pr110308.C
diff --git a/gcc/regcprop.cc b/gcc/regcprop.cc
index 6cbfadb181f..fe75b7f1fa0 100644
--- a/gcc/regcprop.cc
+++ b/gcc/regcprop.cc
@@ -423,7 +423,7 @@ maybe_mode_change (machine_mode orig_mode, machine_mode
copy_mode,
It's unclear if we need to do the same for other special registers. */
if (regno == STACK_POINTER_REGNUM)
{
- if (orig_mode == new_mode)
+ if (orig_mode == new_mode && new_mode == GET_MODE (stack_pointer_rtx))
return stack_pointer_rtx;
else
return NULL_RTX;
@@ -487,9 +487,14 @@ find_oldest_value_reg (enum reg_class cl, rtx reg, struct
value_data *vd)
new_rtx = maybe_mode_change (oldmode, vd->e[regno].mode, mode, i, regno);
if (new_rtx)
{
- ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (reg);
- REG_ATTRS (new_rtx) = REG_ATTRS (reg);
- REG_POINTER (new_rtx) = REG_POINTER (reg);
+ if (new_rtx != stack_pointer_rtx)
+ {
+ ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (reg);
+ REG_ATTRS (new_rtx) = REG_ATTRS (reg);
+ REG_POINTER (new_rtx) = REG_POINTER (reg);
+ }
+ else if (REG_POINTER (new_rtx) != REG_POINTER (reg))
+ return NULL_RTX;
return new_rtx;
}
}
@@ -965,15 +970,27 @@ copyprop_hardreg_forward_1 (basic_block bb, struct
value_data *vd)
if (validate_change (insn, &SET_SRC (set), new_rtx, 0))
{
- ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (src);
- REG_ATTRS (new_rtx) = REG_ATTRS (src);
- REG_POINTER (new_rtx) = REG_POINTER (src);
- if (dump_file)
- fprintf (dump_file,
- "insn %u: replaced reg %u with %u\n",
- INSN_UID (insn), regno, REGNO (new_rtx));
- changed = true;
- goto did_replacement;
+ bool can_change;
+ if (new_rtx != stack_pointer_rtx)
+ {
+ ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (src);
+ REG_ATTRS (new_rtx) = REG_ATTRS (src);
+ REG_POINTER (new_rtx) = REG_POINTER (src);
+ can_change = true;
+ }
+ else
+ can_change
+ = (REG_POINTER (new_rtx) == REG_POINTER (src));
+
+ if (can_change)
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ "insn %u: replaced reg %u with %u\n",
+ INSN_UID (insn), regno, REGNO (new_rtx));
+ changed = true;
+ goto did_replacement;
+ }
}
/* We need to re-extract as validate_change clobbers
recog_data. */
diff --git a/gcc/testsuite/g++.dg/torture/pr110308.C
b/gcc/testsuite/g++.dg/torture/pr110308.C
new file mode 100644
index 00000000000..ddd30d4fc3f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr110308.C
@@ -0,0 +1,30 @@
+/* { dg-do compile } */
+/* { dg-options "-g2 -O2" } */
+
+int channelCount, decodeBlock_outputLength;
+struct BlockCodec {
+ virtual int decodeBlock(const unsigned char *, short *);
+};
+struct ms_adpcm_state {
+ char predictorIndex;
+ int sample1;
+ ms_adpcm_state();
+};
+bool decodeBlock_ok;
+void encodeBlock() { ms_adpcm_state(); }
+struct MSADPCM : BlockCodec {
+ int decodeBlock(const unsigned char *, short *);
+};
+void decodeSample(ms_adpcm_state, bool *);
+int MSADPCM::decodeBlock(const unsigned char *, short *) {
+ ms_adpcm_state decoderState[2];
+ ms_adpcm_state *state[2];
+ state[0] = &decoderState[0];
+ if (channelCount == 2)
+ state[1] = &decoderState[0];
+ short m_coefficients[state[1]->predictorIndex];
+ for (int i = 0; i < channelCount; i++)
+ ++state[i]->sample1;
+ decodeSample(*state[1], &decodeBlock_ok);
+ return decodeBlock_outputLength;
+}
\ No newline at end of file
--
2.34.1
