Mark unionsplit effect-free cases

JuliaLang · Feb 10, 2022 · 93eb06c · 93eb06c
1 parent 37d5613
commit 93eb06c
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Showing 3 changed files with 21 additions and 3 deletions.
diff --git a/base/compiler/abstractinterpretation.jl b/base/compiler/abstractinterpretation.jl
@@ -1971,7 +1971,7 @@ function abstract_eval_global(M::Module, s::Symbol, frame::InferenceState)
     if isdefined(M,s)
         tristate_merge!(frame, Effects(EFFECTS_TOTAL, consistent=ALWAYS_FALSE))
     else
-        tristate_merge!(frame, Effects(EFFECTS_TOTAL, consistent=ALWAYS_FALSE, nothrow=ALWAYS_FALSE, nothrow_if_inbounds=false))
+        tristate_merge!(frame, Effects(EFFECTS_TOTAL, consistent=ALWAYS_FALSE, nothrow=ALWAYS_FALSE, nothrow_if_inbounds=ALWAYS_FALSE))
     end
     return ty
 end

diff --git a/base/compiler/ssair/inlining.jl b/base/compiler/ssair/inlining.jl
@@ -1318,6 +1318,24 @@ function handle_cases!(ir::IRCode, idx::Int, stmt::Expr, @nospecialize(atype),
     if fully_covered && length(cases) == 1
         handle_single_case!(ir, idx, stmt, cases[1].item, todo, params)
     elseif length(cases) > 0
+        all_removable = true
+        for case in cases
+            if isa(case, InvokeCase)
+                effects = case.effects
+            elseif isa(case, InliningTodo)
+                effects = case.spec.effects
+            else
+                continue
+            end
+            if !is_total(case.effects) &&
+               !(is_removable_if_unused(case.effects, ir[SSAValue(idx)][:flag] & IR_FLAG_INBOUNDS != 0))
+                all_removable = false
+                break
+            end
+        end
+        if all_removable
+            ir[SSAValue(idx)][:flag] |= IR_FLAG_EFFECT_FREE
+        end
         push!(todo, idx=>UnionSplit(fully_covered, atype, cases))
     end
     return nothing

diff --git a/base/compiler/types.jl b/base/compiler/types.jl
@@ -43,14 +43,14 @@ struct Effects
     # :consistent before caching. We may want to track it in the future.
     inbounds_taints_consistency::Bool
 end
-Effects(consistent::TriState, effect_free::TriState, nothrow::TriState nothrow_if_inbounds::TriState, terminates::TriState) =
+Effects(consistent::TriState, effect_free::TriState, nothrow::TriState, nothrow_if_inbounds::TriState, terminates::TriState) =
     Effects(consistent, effect_free, nothrow, nothrow_if_inbounds, terminates, false)
 Effects() = Effects(TRISTATE_UNKNOWN, TRISTATE_UNKNOWN, TRISTATE_UNKNOWN, TRISTATE_UNKNOWN, TRISTATE_UNKNOWN)
 
 Effects(e::Effects; consistent::TriState=e.consistent,
     effect_free::TriState = e.effect_free, nothrow::TriState=e.nothrow, nothrow_if_inbounds::TriState=e.nothrow_if_inbounds,
     terminates::TriState=e.terminates, inbounds_taints_consistency::Bool = e.inbounds_taints_consistency) =
-        Effects(consistent, effect_free, nothrow, terminates, inbounds_taints_consistency)
+        Effects(consistent, effect_free, nothrow, nothrow_if_inbounds, terminates, inbounds_taints_consistency)
 
 is_total_or_error(effects::Effects) =
     effects.consistent === ALWAYS_TRUE && effects.effect_free === ALWAYS_TRUE &&