[PATCH] D14807: AMDGPU: Implement SIRegisterInfo::getRegPressureSetScore()

[Tom Stellard via llvm-commits]

tstellarAMD updated this revision to Diff 51375.
tstellarAMD added a comment.

Rebased and address some review comments.  However, register usage is now worse
with this patch.


http://reviews.llvm.org/D14807

Files:
  lib/Target/AMDGPU/SIRegisterInfo.cpp
  lib/Target/AMDGPU/SIRegisterInfo.h

Index: lib/Target/AMDGPU/SIRegisterInfo.h
===================================================================
--- lib/Target/AMDGPU/SIRegisterInfo.h
+++ lib/Target/AMDGPU/SIRegisterInfo.h
@@ -51,6 +51,9 @@
   unsigned getRegPressureSetLimit(const MachineFunction &MF,
                                   unsigned Idx) const override;
 
+  unsigned getRegPressureSetScore(const MachineFunction &MF,
+                                  unsigned PSetID) const override;
+
   bool requiresRegisterScavenging(const MachineFunction &Fn) const override;
 
   bool requiresFrameIndexScavenging(const MachineFunction &MF) const override;
Index: lib/Target/AMDGPU/SIRegisterInfo.cpp
===================================================================
--- lib/Target/AMDGPU/SIRegisterInfo.cpp
+++ lib/Target/AMDGPU/SIRegisterInfo.cpp
@@ -187,6 +187,25 @@
   return VGPRLimit;
 }
 
+unsigned SIRegisterInfo::getRegPressureSetScore(const MachineFunction &MF,
+                                                    unsigned PSetID) const {
+
+  if (SGPRPressureSets.test(PSetID)) {
+    if (VGPRPressureSets.test(PSetID)) {
+      // If a pressure set contains vgprs and sgprs then we prefer incresing
+      // its pressure over regular register classes.  This has the hightest
+      // score.
+      return 2;
+    }
+    // If this is an SGPR pressure set we prefer increasing its pressure
+    // over VGPR pressure sets.
+    return 1;
+  }
+
+  // VGPRS.
+  return 0;
+}
+
 bool SIRegisterInfo::requiresRegisterScavenging(const MachineFunction &Fn) const {
   return Fn.getFrameInfo()->hasStackObjects();
 }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D14807.51375.patch
Type: text/x-patch
Size: 1597 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160323/e06f02fb/attachment.bin>