AMDGPU/SI: Emit the number of SGPR and VGPR spills

Summary:
v2: don't count SGPRs spilled to scratch twice

I think this is sufficient. It doesn't count private memory usage, which
happens often and uses scratch but isn't technically a spill. The private
memory usage can be computed by:
  [scratch_per_thread - vgpr_spills - a random multiple of SGPR spills].

The fact SGPR spills add very high numbers to the scratch size make that
computation a guessing game, but I don't have a solution to that.

Reviewers: tstellarAMD

Subscribers: arsenm, kzhuravl

Differential Revision: http://reviews.llvm.org/D22197

llvm-svn: 275288

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h b/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
index 33d41926440..f5bd6366c71 100644
--- a/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
+++ b/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
@@ -85,6 +85,9 @@ private:
   bool HasNonSpillStackObjects;
   bool HasFlatInstructions;
 
+  unsigned NumSpilledSGPRs;
+  unsigned NumSpilledVGPRs;
+
   // Feature bits required for inputs passed in user SGPRs.
   bool PrivateSegmentBuffer : 1;
   bool DispatchPtr : 1;
@@ -313,6 +316,22 @@ public:
     HasFlatInstructions = UseFlat;
   }
 
+  unsigned getNumSpilledSGPRs() const {
+    return NumSpilledSGPRs;
+  }
+
+  unsigned getNumSpilledVGPRs() const {
+    return NumSpilledVGPRs;
+  }
+
+  void addToSpilledSGPRs(unsigned num) {
+    NumSpilledSGPRs += num;
+  }
+
+  void addToSpilledVGPRs(unsigned num) {
+    NumSpilledVGPRs += num;
+  }
+
   unsigned getPSInputAddr() const {
     return PSInputAddr;
   }