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authorIlia Mirkin <[email protected]>2014-09-30 23:27:25 -0400
committerRob Clark <[email protected]>2014-10-02 21:05:50 -0400
commit3dd9a0d6fdea1ff5b1fe903fce206bf1d1515400 (patch)
tree5e0a288a46c4fbf78b104febbeb12b1b3f6c437f /src/gallium/drivers/freedreno
parentf5eeb8a6dc4d1a1a4b88843e1c8d6d3a9c50512a (diff)
freedreno/ir3: avoid fan-in sources referring to same instruction
Since the RA has to be done s.t. each one gets its own (adjacent) register, it would complicate matters if instructions were allowed to be repeated. This enables copy-propagation use in situations where previously that might have happened. Signed-off-by: Ilia Mirkin <[email protected]> Signed-off-by: Rob Clark <[email protected]>
Diffstat (limited to 'src/gallium/drivers/freedreno')
-rw-r--r--src/gallium/drivers/freedreno/ir3/ir3_cp.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/src/gallium/drivers/freedreno/ir3/ir3_cp.c b/src/gallium/drivers/freedreno/ir3/ir3_cp.c
index 73c2a27c6eb..83bcb7a742b 100644
--- a/src/gallium/drivers/freedreno/ir3/ir3_cp.c
+++ b/src/gallium/drivers/freedreno/ir3/ir3_cp.c
@@ -70,7 +70,7 @@ static void walk_children(struct ir3_instruction *instr, bool keep)
static struct ir3_instruction *
instr_cp_fanin(struct ir3_instruction *instr)
{
- unsigned i;
+ unsigned i, j;
/* we need to handle fanin specially, to detect cases
* when we need to keep a mov
@@ -92,7 +92,15 @@ instr_cp_fanin(struct ir3_instruction *instr)
if (is_meta(cand) && (cand->opc == OPC_META_FO))
cand = instr_cp(src->instr, true);
- src->instr = cand;
+ /* we can't have 2 registers referring to the same instruction, so
+ * go through and check if any already refer to the candidate
+ * instruction. if so, don't do the propagation.
+ */
+ for (j = 1; j < instr->regs_count; j++)
+ if (instr->regs[j]->instr == cand)
+ break;
+ if (j == instr->regs_count)
+ src->instr = cand;
}
}