From a2af42c1d2dc91f4c31e25ff9fff15a89a9b6ead Mon Sep 17 00:00:00 2001 From: Ilia Mirkin Date: Fri, 12 Jun 2015 16:09:05 +0200 Subject: [PATCH] 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 Cc: "10.5 10.6" --- .../nouveau/codegen/nv50_ir_lowering_nvc0.cpp | 16 +++++++++++----- 1 file 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 411e2de1b11..7a5d1ce0299 100644 --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp @@ -168,7 +168,7 @@ NVC0LegalizePostRA::insnDominatedBy(const Instruction *later, void NVC0LegalizePostRA::addTexUse(std::list &uses, - Instruction *usei, const Instruction *insn) + Instruction *usei, const Instruction *texi) { bool add = true; for (std::list::iterator it = uses.begin(); @@ -183,7 +183,7 @@ NVC0LegalizePostRA::addTexUse(std::list &uses, ++it; } if (add) - uses.push_back(TexUse(usei, insn)); + uses.push_back(TexUse(usei, texi)); } void @@ -195,7 +195,8 @@ 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) { @@ -243,7 +244,12 @@ 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) @@ -262,7 +268,7 @@ NVC0LegalizePostRA::findFirstUses( usei->subOp != NV50_IR_SUBOP_MOV_FINAL) { findFirstUses(texi, usei, uses, visited); } else { - addTexUse(uses, usei, insn); + addTexUse(uses, usei, texi); } } } -- 2.30.2