MIR Optimise - Slight optimisation

3 files changed, 28 insertions, 13 deletions

diff --git a/src/mir/helpers.cpp b/src/mir/helpers.cpp
index 1e43e361..2cb55e4a 100644
--- a/src/mir/helpers.cpp
+++ b/src/mir/helpers.cpp
@@ -557,7 +557,7 @@ namespace
 #if 1
 void MIR_Helper_GetLifetimes_DetermineValueLifetime(::MIR::TypeResolve& state, const ::MIR::Function& fcn,  size_t bb_idx, size_t stmt_idx,  const ::MIR::LValue& lv, const ::std::vector<size_t>& block_offsets, ValueLifetime& vl);
 
-::MIR::ValueLifetimes MIR_Helper_GetLifetimes(::MIR::TypeResolve& state, const ::MIR::Function& fcn, bool dump_debug)
+::MIR::ValueLifetimes MIR_Helper_GetLifetimes(::MIR::TypeResolve& state, const ::MIR::Function& fcn, bool dump_debug, const ::std::vector<bool>* mask/*=nullptr*/)
 {
     TRACE_FUNCTION_F(state);
 
@@ -580,8 +580,11 @@ void MIR_Helper_GetLifetimes_DetermineValueLifetime(::MIR::TypeResolve& state, c
                 // NOTE: Fills the first statement after running, just to ensure that any assigned value has _a_ lifetime
                 if( const auto* de = lv.opt_Local() )
                 {
-                    MIR_Helper_GetLifetimes_DetermineValueLifetime(state, fcn, bb_idx, stmt_idx,  lv, block_offsets, slot_lifetimes[*de]);
-                    slot_lifetimes[*de].fill(block_offsets, bb_idx, stmt_idx, stmt_idx);
+                    if( !mask || mask->at(*de) )
+                    {
+                        MIR_Helper_GetLifetimes_DetermineValueLifetime(state, fcn, bb_idx, stmt_idx,  lv, block_offsets, slot_lifetimes[*de]);
+                        slot_lifetimes[*de].fill(block_offsets, bb_idx, stmt_idx, stmt_idx);
+                    }
                 }
                 else
                 {
@@ -591,8 +594,11 @@ void MIR_Helper_GetLifetimes_DetermineValueLifetime(::MIR::TypeResolve& state, c
                         {
                             if( vu == ValUsage::Write )
                             {
-                                MIR_Helper_GetLifetimes_DetermineValueLifetime(state, fcn, bb_idx, stmt_idx,  lv, block_offsets, slot_lifetimes[*de]);
-                                slot_lifetimes[*de].fill(block_offsets, bb_idx, stmt_idx, stmt_idx);
+                                if( !mask || mask->at(*de) )
+                                {
+                                    MIR_Helper_GetLifetimes_DetermineValueLifetime(state, fcn, bb_idx, stmt_idx,  lv, block_offsets, slot_lifetimes[*de]);
+                                    slot_lifetimes[*de].fill(block_offsets, bb_idx, stmt_idx, stmt_idx);
+                                }
                             }
                         }
                         return false;
@@ -622,7 +628,10 @@ void MIR_Helper_GetLifetimes_DetermineValueLifetime(::MIR::TypeResolve& state, c
                 // HACK: Mark values as valid wherever there's a drop (prevents confusion by simple validator)
                 if( const auto* de = se->slot.opt_Local() )
                 {
-                    slot_lifetimes[*de].fill(block_offsets, bb_idx, stmt_idx,stmt_idx);
+                    if( !mask || mask->at(*de) )
+                    {
+                        slot_lifetimes[*de].fill(block_offsets, bb_idx, stmt_idx,stmt_idx);
+                    }
                 }
             }
         }
diff --git a/src/mir/helpers.hpp b/src/mir/helpers.hpp
index 12fd4ddf..f845e790 100644
--- a/src/mir/helpers.hpp
+++ b/src/mir/helpers.hpp
@@ -184,4 +184,4 @@ namespace visit {
 
 }   // namespace MIR
 
-extern ::MIR::ValueLifetimes MIR_Helper_GetLifetimes(::MIR::TypeResolve& state, const ::MIR::Function& fcn, bool dump_debug);
+extern ::MIR::ValueLifetimes MIR_Helper_GetLifetimes(::MIR::TypeResolve& state, const ::MIR::Function& fcn, bool dump_debug, const ::std::vector<bool>* mask=nullptr);
diff --git a/src/mir/optimise.cpp b/src/mir/optimise.cpp
index dc3967b4..6601c03b 100644
--- a/src/mir/optimise.cpp
+++ b/src/mir/optimise.cpp
@@ -574,11 +574,16 @@ void MIR_Optimise(const StaticTraitResolve& resolve, const ::HIR::ItemPath& path
 
         // >> Unify duplicate temporaries
         // If two temporaries don't overlap in lifetime (blocks in which they're valid), unify the two
-        // TODO: Only run this when nothing else happened. (It's VERY expensive)
-        change_happened |= MIR_Optimise_UnifyTemporaries(state, fcn);
-        #if CHECK_AFTER_ALL
-        MIR_Validate(resolve, path, fcn, args, ret_type);
-        #endif
+        // Only run this when nothing else happened. (It's VERY expensive)
+#if 1
+        if( !change_happened )
+        {
+            change_happened |= MIR_Optimise_UnifyTemporaries(state, fcn);
+# if CHECK_AFTER_ALL
+            MIR_Validate(resolve, path, fcn, args, ret_type);
+# endif
+        }
+#endif
 
         // >> Combine Duplicate Blocks
         change_happened |= MIR_Optimise_UnifyBlocks(state, fcn);
@@ -1254,7 +1259,8 @@ bool MIR_Optimise_UnifyTemporaries(::MIR::TypeResolve& state, ::MIR::Function& f
             return false;
     }
 
-    auto lifetimes = MIR_Helper_GetLifetimes(state, fcn, /*dump_debug=*/true);
+    // TODO: Only calculate lifetimes for replacable locals
+    auto lifetimes = MIR_Helper_GetLifetimes(state, fcn, /*dump_debug=*/true, /*mask=*/&replacable);
     ::std::vector<::MIR::ValueLifetime>  slot_lifetimes = mv$(lifetimes.m_slots);
 
     // 2. Unify variables of the same type with distinct non-overlapping lifetimes