commit 1873560a5b49434905d52460532c7fcce9b7e6de
author Jim Stichnoth <stichnot@chromium.org> Tue Sep 16 19:59:35 2014 -0700
committer Jim Stichnoth <stichnot@chromium.org> Tue Sep 16 19:59:35 2014 -0700
tree 10fbfa0509d8b0cfd6e698be676802c229d31615
parent bc004630f011e69deeca08428e59e15a4a602c1e

Subzero: Add rudimentary statistics on generated code.

The following are collected:
- Number of machine instructions emitted
- Number of registers saved/restored in prolog/epilog
- Number of stack frame bytes (non-alloca) allocated
- Number of "spills", or stores to stack slots
- Number of "fills", or loads/operations from stack slots
- Fill+Spill count (sum of above two)

These are somewhat reasonable approximations of code quality, and the primary intention is to compare before-and-after when trying out an optimization.

The statistics are dumped after translating each function.  Per-function and cumulative statistics are collected.  The output lines have a prefix that is easy to filter.

BUG= none
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/580633002

src/IceCfgNode.cpp

diff --git a/src/IceCfgNode.cpp b/src/IceCfgNode.cpp
index f6b4a98..4de2f57 100644
--- a/src/IceCfgNode.cpp
+++ b/src/IceCfgNode.cpp
@@ -483,6 +483,21 @@
     if (Inst->isRedundantAssign())
       continue;
     (*I)->emit(Func);
+    // Update emitted instruction count, plus fill/spill count for
+    // Variable operands without a physical register.
+    if (uint32_t Count = (*I)->getEmitInstCount()) {
+      Func->getContext()->statsUpdateEmitted(Count);
+      if (Variable *Dest = (*I)->getDest()) {
+        if (!Dest->hasReg())
+          Func->getContext()->statsUpdateFills();
+      }
+      for (SizeT S = 0; S < (*I)->getSrcSize(); ++S) {
+        if (Variable *Src = llvm::dyn_cast<Variable>((*I)->getSrc(S))) {
+          if (!Src->hasReg())
+            Func->getContext()->statsUpdateSpills();
+        }
+      }
+    }
   }
 }