Generalize dead stores.

Stores are dead if the address is from an alloca and all uses of the
address are stores, not just when it's a single store.

Change-Id: I5b65a64e21b9e398922e5440c35f0d318c03e911
Reviewed-on: https://swiftshader-review.googlesource.com/8574
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>

diff --git a/src/Reactor/Optimizer.cpp b/src/Reactor/Optimizer.cpp
index fa12a92..38e24ef 100644 (file)
--- a/src/Reactor/Optimizer.cpp
+++ b/src/Reactor/Optimizer.cpp
@@ -456,7 +456,7 @@ namespace
 
                                if(def && llvm::isa<Ice::InstAlloca>(def))
                                {
-                                       return uses[address].size() == 1;   // Dead if this store is the only use
+                                       return uses[address].size() == uses[address].stores.size();   // Dead if all uses are stores
                                }
                        }
                }