Mesa (master): nvir/gm107: consider FILE_FLAGS dependencies in SchedDataCalculatorGM107

[Karol Herbst]

Module: Mesa
Branch: master
Commit: ef308d40070014b92aaf07a228edc73bd2e85570
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=ef308d40070014b92aaf07a228edc73bd2e85570

Author: Karol Herbst <kherbst at redhat.com>
Date:   Tue Dec  5 11:09:54 2017 +0100

nvir/gm107: consider FILE_FLAGS dependencies in SchedDataCalculatorGM107

currently while insterting barriers, writes and reads to FILE_FLAGS aren't
considered. This can lead to WaR hazards in some situations.

With the previous commit fixes shaders with intstructions like this:
  mad u32 $r2 $r4 $r11 $r2
  mad u32 { $r5 $c0 } $r4 $r10 $r6
  mad (SUBOP:1) u32 $r3 $r4 $r10 $r2 $c0

Affects OpenCL CTS tests on Maxwell+:
basic/test_basic intmath_long
basic/test_basic intmath_long2
basic/test_basic intmath_long4

v2: only put barriers on instructions which actually read flags

Reviewed-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Signed-off-by: Karol Herbst <kherbst at redhat.com>

---

 .../drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp        | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
index 96bd276884..fafece81ad 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
@@ -3944,6 +3944,7 @@ SchedDataCalculatorGM107::needWrDepBar(const Instruction *insn) const
 
    for (int d = 0; insn->defExists(d); ++d) {
       if (insn->def(d).getFile() == FILE_GPR ||
+          insn->def(d).getFile() == FILE_FLAGS ||
           insn->def(d).getFile() == FILE_PREDICATE)
          return true;
    }
@@ -3983,6 +3984,12 @@ SchedDataCalculatorGM107::findFirstUse(const Instruction *bari) const
                   continue;
                return insn;
             }
+            if (def.getFile() == FILE_FLAGS) {
+               if (insn->src(s).getFile() != FILE_FLAGS ||
+                   src->reg.data.id != minGPR)
+                  continue;
+               return insn;
+            }
          }
       }
    }
@@ -4002,7 +4009,8 @@ SchedDataCalculatorGM107::findFirstDef(const Instruction *bari) const
 
       for (int d = 0; insn->defExists(d); ++d) {
          const Value *def = insn->def(d).rep();
-         if (insn->def(d).getFile() != FILE_GPR)
+         if (insn->def(d).getFile() != FILE_GPR &&
+             insn->def(d).getFile() != FILE_FLAGS)
             continue;
 
          minGPR = def->reg.data.id;
@@ -4010,7 +4018,12 @@ SchedDataCalculatorGM107::findFirstDef(const Instruction *bari) const
 
          for (int s = 0; bari->srcExists(s); ++s) {
             const Value *src = bari->src(s).rep();
+            if (bari->src(s).getFile() == FILE_FLAGS &&
+                insn->def(d).getFile() == FILE_FLAGS &&
+                src->reg.data.id == minGPR)
+               return insn;
             if (bari->src(s).getFile() != FILE_GPR ||
+                insn->def(d).getFile() != FILE_GPR ||
                 src->reg.data.id + src->reg.size / 4 - 1 < minGPR ||
                 src->reg.data.id > maxGPR)
                continue;