Replace legacy ConstProp by GVN.

Author: cjgillot

compiler/rustc_mir_transform/src/const_prop.rs

@@ -553,7 +553,6 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
             &separate_const_switch::SeparateConstSwitch,
             &gvn::GVN,
             &simplify::SimplifyLocals::AfterGVN,
-            &const_prop::ConstProp,
             &dataflow_const_prop::DataflowConstProp,
             //
             // Const-prop runs unconditionally, but doesn't mutate the MIR at mir-opt-level=0.

compiler/rustc_mir_transform/src/lib.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Zmir-enable-passes=+Inline,+ConstProp --crate-type lib
+// compile-flags: -Zmir-enable-passes=+Inline,+GVN --crate-type lib
 // revisions: ASSERT NOASSERT
 //[ASSERT] compile-flags: -Coverflow-checks=on
 //[NOASSERT] compile-flags: -Coverflow-checks=off

tests/codegen/inherit_overflow.rs

@@ -1,4 +1,4 @@
-// MIR for `main` after ConstProp
+// MIR for `main` after GVN
 
 fn main() -> () {
     let mut _0: ();

tests/mir-opt/const_allocation.main.ConstProp.after.32bit.mir renamed to tests/mir-opt/const_allocation.main.GVN.after.32bit.mir

@@ -1,4 +1,4 @@
-// MIR for `main` after ConstProp
+// MIR for `main` after GVN
 
 fn main() -> () {
     let mut _0: ();

tests/mir-opt/const_allocation.main.ConstProp.after.64bit.mir renamed to tests/mir-opt/const_allocation.main.GVN.after.64bit.mir

@@ -1,10 +1,10 @@
-// unit-test: ConstProp
+// unit-test: GVN
 // ignore-endian-big
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
 static FOO: &[(Option<i32>, &[&str])] =
     &[(None, &[]), (None, &["foo", "bar"]), (Some(42), &["meh", "mop", "möp"])];
 
-// EMIT_MIR const_allocation.main.ConstProp.after.mir
+// EMIT_MIR const_allocation.main.GVN.after.mir
 fn main() {
     FOO;
 }

tests/mir-opt/const_allocation.rs

@@ -1,4 +1,4 @@
-// MIR for `main` after ConstProp
+// MIR for `main` after GVN
 
 fn main() -> () {
     let mut _0: ();

tests/mir-opt/const_allocation2.main.ConstProp.after.32bit.mir renamed to tests/mir-opt/const_allocation2.main.GVN.after.32bit.mir

@@ -1,4 +1,4 @@
-// MIR for `main` after ConstProp
+// MIR for `main` after GVN
 
 fn main() -> () {
     let mut _0: ();

tests/mir-opt/const_allocation2.main.ConstProp.after.64bit.mir renamed to tests/mir-opt/const_allocation2.main.GVN.after.64bit.mir

@@ -1,7 +1,7 @@
-// unit-test: ConstProp
+// unit-test: GVN
 // ignore-endian-big
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
-// EMIT_MIR const_allocation2.main.ConstProp.after.mir
+// EMIT_MIR const_allocation2.main.GVN.after.mir
 fn main() {
     FOO;
 }

tests/mir-opt/const_allocation2.rs

@@ -1,4 +1,4 @@
-// MIR for `main` after ConstProp
+// MIR for `main` after GVN
 
 fn main() -> () {
     let mut _0: ();