From 3532c3533a00b553d1ffb28345f903a1501e1cd7 Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Wed, 30 Aug 2017 14:33:54 -0700
Subject: [PATCH] Teach simple_gvn that iconst.i32 is not congruent to
 iconst.i64.

---
 cranelift/filetests/simple_gvn/reject.cton | 14 ++++++++++++++
 lib/cretonne/src/ir/types.rs               |  2 +-
 lib/cretonne/src/simple_gvn.rs             |  7 ++++---
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/cranelift/filetests/simple_gvn/reject.cton b/cranelift/filetests/simple_gvn/reject.cton
index 755891ad5d..1bb6ad16fa 100644
--- a/cranelift/filetests/simple_gvn/reject.cton
+++ b/cranelift/filetests/simple_gvn/reject.cton
@@ -9,3 +9,17 @@ ebb0(v0: i32):
 ; check: regmove v0, %10 -> %20
     return v0
 }
+
+function %differing_typevars() -> i64 {
+ebb0:
+    v0 = iconst.i32 7
+    v1 = iconst.i64 7
+    v2 = iconst.i64 8
+; check: v0 = iconst.i32 7
+; check: v1 = iconst.i64 7
+; check: v2 = iconst.i64 8
+    v3 = uextend.i64 v0
+    v4 = iadd v2, v1
+    v5 = iadd v4, v3
+    return v5
+}
diff --git a/lib/cretonne/src/ir/types.rs b/lib/cretonne/src/ir/types.rs
index 0007154025..275ec70c9b 100644
--- a/lib/cretonne/src/ir/types.rs
+++ b/lib/cretonne/src/ir/types.rs
@@ -23,7 +23,7 @@ use std::fmt::{self, Display, Debug, Formatter};
 ///
 /// SIMD vector types have power-of-two lanes, up to 256. Lanes can be any int/float/bool type.
 ///
-#[derive(Copy, Clone, PartialEq, Eq)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Type(u8);
 
 /// No type. Used for functions without a return value. Can't be loaded or stored. Can't be part of
diff --git a/lib/cretonne/src/simple_gvn.rs b/lib/cretonne/src/simple_gvn.rs
index 2d1c5a7e61..8a8022ed2d 100644
--- a/lib/cretonne/src/simple_gvn.rs
+++ b/lib/cretonne/src/simple_gvn.rs
@@ -2,7 +2,7 @@
 
 use flowgraph::ControlFlowGraph;
 use dominator_tree::DominatorTree;
-use ir::{Cursor, CursorBase, InstructionData, Function, Inst, Opcode};
+use ir::{Cursor, CursorBase, InstructionData, Function, Inst, Opcode, Type};
 use std::collections::HashMap;
 
 /// Test whether the given opcode is unsafe to even consider for GVN.
@@ -14,7 +14,7 @@ fn trivially_unsafe_for_gvn(opcode: Opcode) -> bool {
 /// Perform simple GVN on `func`.
 ///
 pub fn do_simple_gvn(func: &mut Function, cfg: &mut ControlFlowGraph) {
-    let mut visible_values: HashMap<InstructionData, Inst> = HashMap::new();
+    let mut visible_values: HashMap<(InstructionData, Type), Inst> = HashMap::new();
 
     let domtree = DominatorTree::with_function(func, cfg);
 
@@ -26,6 +26,7 @@ pub fn do_simple_gvn(func: &mut Function, cfg: &mut ControlFlowGraph) {
 
         while let Some(inst) = pos.next_inst() {
             let opcode = func.dfg[inst].opcode();
+            let ctrl_typevar = func.dfg.ctrl_typevar(inst);
 
             // Resolve aliases, particularly aliases we created earlier.
             func.dfg.resolve_aliases_in_arguments(inst);
@@ -42,7 +43,7 @@ pub fn do_simple_gvn(func: &mut Function, cfg: &mut ControlFlowGraph) {
                 continue;
             }
 
-            let key = func.dfg[inst].clone();
+            let key = (func.dfg[inst].clone(), ctrl_typevar);
             let entry = visible_values.entry(key);
             use std::collections::hash_map::Entry::*;
             match entry {