Simplify cast_shift_expr_rhs.

It's only ever used with shift operators.
rust-lang · Oct 25, 2022 · 6cd35ac · 6cd35ac
1 parent 8c02f4d
commit 6cd35ac
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Showing 2 changed files with 18 additions and 24 deletions.
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
@@ -337,31 +337,26 @@ pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 
 pub fn cast_shift_expr_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
  bx: &mut Bx,
- op: hir::BinOpKind,
  lhs: Bx::Value,
  rhs: Bx::Value,
 ) -> Bx::Value {
  // Shifts may have any size int on the rhs
- if op.is_shift() {
- let mut rhs_llty = bx.cx().val_ty(rhs);
- let mut lhs_llty = bx.cx().val_ty(lhs);
- if bx.cx().type_kind(rhs_llty) == TypeKind::Vector {
- rhs_llty = bx.cx().element_type(rhs_llty)
- }
- if bx.cx().type_kind(lhs_llty) == TypeKind::Vector {
- lhs_llty = bx.cx().element_type(lhs_llty)
- }
- let rhs_sz = bx.cx().int_width(rhs_llty);
- let lhs_sz = bx.cx().int_width(lhs_llty);
- if lhs_sz < rhs_sz {
- bx.trunc(rhs, lhs_llty)
- } else if lhs_sz > rhs_sz {
- // FIXME (#1877: If in the future shifting by negative
- // values is no longer undefined then this is wrong.
- bx.zext(rhs, lhs_llty)
- } else {
- rhs
- }
+ let mut rhs_llty = bx.cx().val_ty(rhs);
+ let mut lhs_llty = bx.cx().val_ty(lhs);
+ if bx.cx().type_kind(rhs_llty) == TypeKind::Vector {
+ rhs_llty = bx.cx().element_type(rhs_llty)
+ }
+ if bx.cx().type_kind(lhs_llty) == TypeKind::Vector {
+ lhs_llty = bx.cx().element_type(lhs_llty)
+ }
+ let rhs_sz = bx.cx().int_width(rhs_llty);
+ let lhs_sz = bx.cx().int_width(lhs_llty);
+ if lhs_sz < rhs_sz {
+ bx.trunc(rhs, lhs_llty)
+ } else if lhs_sz > rhs_sz {
+ // FIXME (#1877: If in the future shifting by negative
+ // values is no longer undefined then this is wrong.
+ bx.zext(rhs, lhs_llty)
  } else {
  rhs
  }

diff --git a/compiler/rustc_codegen_ssa/src/common.rs b/compiler/rustc_codegen_ssa/src/common.rs
@@ -1,7 +1,6 @@
 #![allow(non_camel_case_types)]
 
 use rustc_errors::struct_span_err;
-use rustc_hir as hir;
 use rustc_hir::LangItem;
 use rustc_middle::mir::interpret::ConstValue;
 use rustc_middle::ty::{self, layout::TyAndLayout, Ty, TyCtxt};
@@ -140,7 +139,7 @@ pub fn build_unchecked_lshift<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
  lhs: Bx::Value,
  rhs: Bx::Value,
 ) -> Bx::Value {
- let rhs = base::cast_shift_expr_rhs(bx, hir::BinOpKind::Shl, lhs, rhs);
+ let rhs = base::cast_shift_expr_rhs(bx, lhs, rhs);
  // #1877, #10183: Ensure that input is always valid
  let rhs = shift_mask_rhs(bx, rhs);
  bx.shl(lhs, rhs)
@@ -152,7 +151,7 @@ pub fn build_unchecked_rshift<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
  lhs: Bx::Value,
  rhs: Bx::Value,
 ) -> Bx::Value {
- let rhs = base::cast_shift_expr_rhs(bx, hir::BinOpKind::Shr, lhs, rhs);
+ let rhs = base::cast_shift_expr_rhs(bx, lhs, rhs);
  // #1877, #10183: Ensure that input is always valid
  let rhs = shift_mask_rhs(bx, rhs);
  let is_signed = lhs_t.is_signed();