R600/SI: Disable register pressure tracking in the schedulersched-perf-Mar-27-2015

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/Target/R600/AMDGPUSubtarget.cpp b/lib/Target/R600/AMDGPUSubtarget.cpp
index 0ead65209e1..15def380a48 100644
--- a/lib/Target/R600/AMDGPUSubtarget.cpp
+++ b/lib/Target/R600/AMDGPUSubtarget.cpp
@@ -119,10 +119,10 @@ void AMDGPUSubtarget::overrideSchedPolicy(MachineSchedPolicy &Policy,
                                           unsigned NumRegionInstrs) const {
   if (getGeneration() >= SOUTHERN_ISLANDS) {
 
-    // Track register pressure so the scheduler can try to decrease
-    // pressure once register usage is above the threshold defined by
-    // SIRegisterInfo::getRegPressureSetLimit()
-    Policy.ShouldTrackPressure = true;
+    // FIXME: Register pressure tracking seems to lead to worse code.
+    // I think part of the issue is that our RegPressureSet limits are too
+    // low, so we are almost always in REG-CRITICAL state.
+    Policy.ShouldTrackPressure = false;
 
     // Enabling both top down and bottom up scheduling seems to give us less
     // register spills than just using one of these approaches on its own.