Attachment 105404 Details for Bug 83079 – avoid infinite recursion in findFirstUses

[patch] avoid infinite recursion in findFirstUses

0001-nvc0-ir-avoid-infinite-recursion-when-finding-first-.patch (text/plain), 4.12 KB, created by Ilia Mirkin on 2014-08-29 03:10:14 UTC

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Creator: Ilia Mirkin

Created: 2014-08-29 03:10:14 UTC

Size: 4.12 KB

patch

obsolete

>From 6a59659b5ca039c6e5b56e7b9f5ca0a36e6440e6 Mon Sep 17 00:00:00 2001
>From: Ilia Mirkin <imirkin@alum.mit.edu>
>Date: Thu, 28 Aug 2014 23:05:49 -0400
>Subject: [PATCH] nvc0/ir: avoid infinite recursion when finding first uses of
> tex
>
>In certain circumstances, findFirstUses could end up doubling back down
>instructions it had already processed, resulting in an infinite
>recursion. Avoid this by keeping track of already-visited instructions.
>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83079
>Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
>---
> .../nouveau/codegen/nv50_ir_lowering_nvc0.cpp      | 23 +++++++++++++++-------
> .../nouveau/codegen/nv50_ir_lowering_nvc0.h        |  5 ++++-
> 2 files changed, 20 insertions(+), 8 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 7da9b0b..e081d59 100644
>--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
>+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
>@@ -174,15 +174,22 @@ NVC0LegalizePostRA::findOverwritingDefs(const Instruction *texi,
> }
> 
> void
>-NVC0LegalizePostRA::findFirstUses(const Instruction *texi,
>-                                  const Instruction *insn,
>-                                  std::list<TexUse> &uses)
>+NVC0LegalizePostRA::findFirstUses(
>+      const Instruction *texi,
>+      const Instruction *insn,
>+      std::list<TexUse> &uses,
>+      std::tr1::unordered_set<const Instruction *>& visited)
> {
>    for (int d = 0; insn->defExists(d); ++d) {
>       Value *v = insn->getDef(d);
>       for (Value::UseIterator u = v->uses.begin(); u != v->uses.end(); ++u) {
>          Instruction *usei = (*u)->getInsn();
> 
>+         if (visited.find(usei) != visited.end())
>+            continue;
>+
>+         visited.insert(usei);
>+
>          if (usei->op == OP_PHI || usei->op == OP_UNION) {
>             // need a barrier before WAW cases
>             for (int s = 0; usei->srcExists(s); ++s) {
>@@ -197,11 +204,11 @@ NVC0LegalizePostRA::findFirstUses(const Instruction *texi,
>              usei->op == OP_PHI ||
>              usei->op == OP_UNION) {
>             // these uses don't manifest in the machine code
>-            findFirstUses(texi, usei, uses);
>+            findFirstUses(texi, usei, uses, visited);
>          } else
>          if (usei->op == OP_MOV && usei->getDef(0)->equals(usei->getSrc(0)) &&
>              usei->subOp != NV50_IR_SUBOP_MOV_FINAL) {
>-            findFirstUses(texi, usei, uses);
>+            findFirstUses(texi, usei, uses, visited);
>          } else {
>             addTexUse(uses, usei, insn);
>          }
>@@ -257,8 +264,10 @@ NVC0LegalizePostRA::insertTextureBarriers(Function *fn)
>    uses = new std::list<TexUse>[texes.size()];
>    if (!uses)
>       return false;
>-   for (size_t i = 0; i < texes.size(); ++i)
>-      findFirstUses(texes[i], texes[i], uses[i]);
>+   for (size_t i = 0; i < texes.size(); ++i) {
>+      std::tr1::unordered_set<const Instruction *> visited;
>+      findFirstUses(texes[i], texes[i], uses[i], visited);
>+   }
> 
>    // determine the barrier level at each use
>    for (size_t i = 0; i < texes.size(); ++i) {
>diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h
>index 7f39c28..d8ff5cd 100644
>--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h
>+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h
>@@ -20,6 +20,8 @@
>  * OTHER DEALINGS IN THE SOFTWARE.
>  */
> 
>+#include <tr1/unordered_set>
>+
> #include "codegen/nv50_ir.h"
> #include "codegen/nv50_ir_build_util.h"
> 
>@@ -69,7 +71,8 @@ private:
>    bool insertTextureBarriers(Function *);
>    inline bool insnDominatedBy(const Instruction *, const Instruction *) const;
>    void findFirstUses(const Instruction *tex, const Instruction *def,
>-                      std::list<TexUse>&);
>+                      std::list<TexUse>&,
>+                      std::tr1::unordered_set<const Instruction *>&);
>    void findOverwritingDefs(const Instruction *tex, Instruction *insn,
>                             const BasicBlock *term,
>                             std::list<TexUse>&);
>-- 
>1.8.5.5
>

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Attachments on bug 83079: 105398 | 105404

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