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authorIlia Mirkin <imirkin@alum.mit.edu>2015-06-12 16:09:05 +0200
committerEmil Velikov <emil.l.velikov@gmail.com>2015-06-18 13:43:48 +0100
commitb26bac8b1e094b8400c2f5dfa22283c23dda4080 (patch)
treea68c9192d9eb23fa230360d3e1ac9f6769b312db
parent20fd2abdd6dce03db7ad79375ddfc27b4b4926dc (diff)
nvc0/ir: fix collection of first uses for texture barrier insertion
One of the places we have to insert texbars is in situations where the result of the tex gets overwritten by a different instruction (e.g. in a conditional statement). However in some situations it can actually appear as though the original tex itself is an overwriting instruction. This can naturally never really happen, so just ignore the tex instruction when it comes up. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90347 Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu> Cc: "10.5 10.6" <mesa-stable@lists.freedesktop.org> (cherry picked from commit a2af42c1d2dc91f4c31e25ff9fff15a89a9b6ead)
-rw-r--r--src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp16
1 files changed, 11 insertions, 5 deletions
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
index 8ae594caf5..5ef5e2a0d4 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
@@ -145,7 +145,7 @@ NVC0LegalizePostRA::insnDominatedBy(const Instruction *later,
void
NVC0LegalizePostRA::addTexUse(std::list<TexUse> &uses,
- Instruction *usei, const Instruction *insn)
+ Instruction *usei, const Instruction *texi)
{
bool add = true;
for (std::list<TexUse>::iterator it = uses.begin();
@@ -160,7 +160,7 @@ NVC0LegalizePostRA::addTexUse(std::list<TexUse> &uses,
++it;
}
if (add)
- uses.push_back(TexUse(usei, insn));
+ uses.push_back(TexUse(usei, texi));
}
void
@@ -172,7 +172,8 @@ NVC0LegalizePostRA::findOverwritingDefs(const Instruction *texi,
while (insn->op == OP_MOV && insn->getDef(0)->equals(insn->getSrc(0)))
insn = insn->getSrc(0)->getUniqueInsn();
- if (!insn->bb->reachableBy(texi->bb, term))
+ // NOTE: the tex itself is, of course, not an overwriting definition
+ if (insn == texi || !insn->bb->reachableBy(texi->bb, term))
return;
switch (insn->op) {
@@ -220,7 +221,12 @@ NVC0LegalizePostRA::findFirstUses(
visited.insert(usei);
if (usei->op == OP_PHI || usei->op == OP_UNION) {
- // need a barrier before WAW cases
+ // need a barrier before WAW cases, like:
+ // %r0 = tex
+ // if ...
+ // texbar <- is required or tex might replace x again
+ // %r1 = x <- overwriting def
+ // %r2 = phi %r0, %r1
for (int s = 0; usei->srcExists(s); ++s) {
Instruction *defi = usei->getSrc(s)->getUniqueInsn();
if (defi && &usei->src(s) != *u)
@@ -239,7 +245,7 @@ NVC0LegalizePostRA::findFirstUses(
usei->subOp != NV50_IR_SUBOP_MOV_FINAL) {
findFirstUses(texi, usei, uses, visited);
} else {
- addTexUse(uses, usei, insn);
+ addTexUse(uses, usei, texi);
}
}
}