From c3de4b3aad6a2be86d4711086267e21660bf2b23 Mon Sep 17 00:00:00 2001 From: Camille GILLOT Date: Sun, 2 Jun 2024 12:40:07 +0000 Subject: [PATCH] Handle all GVN binops in a single place. --- compiler/rustc_mir_transform/src/gvn.rs | 70 ++++++++++++++----------- 1 file changed, 40 insertions(+), 30 deletions(-) diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs index fadb5edefdfb1..548e4e309360e 100644 --- a/compiler/rustc_mir_transform/src/gvn.rs +++ b/compiler/rustc_mir_transform/src/gvn.rs @@ -223,7 +223,6 @@ enum Value<'tcx> { NullaryOp(NullOp<'tcx>, Ty<'tcx>), UnaryOp(UnOp, VnIndex), BinaryOp(BinOp, VnIndex, VnIndex), - CheckedBinaryOp(BinOp, VnIndex, VnIndex), // FIXME get rid of this, work like MIR instead Cast { kind: CastKind, value: VnIndex, @@ -508,17 +507,6 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { let val = self.ecx.binary_op(bin_op, &lhs, &rhs).ok()?; val.into() } - CheckedBinaryOp(bin_op, lhs, rhs) => { - let lhs = self.evaluated[lhs].as_ref()?; - let lhs = self.ecx.read_immediate(lhs).ok()?; - let rhs = self.evaluated[rhs].as_ref()?; - let rhs = self.ecx.read_immediate(rhs).ok()?; - let val = self - .ecx - .binary_op(bin_op.wrapping_to_overflowing().unwrap(), &lhs, &rhs) - .ok()?; - val.into() - } Cast { kind, value, from: _, to } => match kind { CastKind::IntToInt | CastKind::IntToFloat => { let value = self.evaluated[value].as_ref()?; @@ -829,17 +817,10 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { let lhs = lhs?; let rhs = rhs?; - if let Some(op) = op.overflowing_to_wrapping() { - if let Some(value) = self.simplify_binary(op, true, ty, lhs, rhs) { - return Some(value); - } - Value::CheckedBinaryOp(op, lhs, rhs) - } else { - if let Some(value) = self.simplify_binary(op, false, ty, lhs, rhs) { - return Some(value); - } - Value::BinaryOp(op, lhs, rhs) + if let Some(value) = self.simplify_binary(op, ty, lhs, rhs) { + return Some(value); } + Value::BinaryOp(op, lhs, rhs) } Rvalue::UnaryOp(op, ref mut arg) => { let arg = self.simplify_operand(arg, location)?; @@ -970,7 +951,6 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { fn simplify_binary( &mut self, op: BinOp, - checked: bool, lhs_ty: Ty<'tcx>, lhs: VnIndex, rhs: VnIndex, @@ -999,22 +979,39 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { use Either::{Left, Right}; let a = as_bits(lhs).map_or(Right(lhs), Left); let b = as_bits(rhs).map_or(Right(rhs), Left); + let result = match (op, a, b) { // Neutral elements. - (BinOp::Add | BinOp::BitOr | BinOp::BitXor, Left(0), Right(p)) + ( + BinOp::Add + | BinOp::AddWithOverflow + | BinOp::AddUnchecked + | BinOp::BitOr + | BinOp::BitXor, + Left(0), + Right(p), + ) | ( BinOp::Add + | BinOp::AddWithOverflow + | BinOp::AddUnchecked | BinOp::BitOr | BinOp::BitXor | BinOp::Sub + | BinOp::SubWithOverflow + | BinOp::SubUnchecked | BinOp::Offset | BinOp::Shl | BinOp::Shr, Right(p), Left(0), ) - | (BinOp::Mul, Left(1), Right(p)) - | (BinOp::Mul | BinOp::Div, Right(p), Left(1)) => p, + | (BinOp::Mul | BinOp::MulWithOverflow | BinOp::MulUnchecked, Left(1), Right(p)) + | ( + BinOp::Mul | BinOp::MulWithOverflow | BinOp::MulUnchecked | BinOp::Div, + Right(p), + Left(1), + ) => p, // Attempt to simplify `x & ALL_ONES` to `x`, with `ALL_ONES` depending on type size. (BinOp::BitAnd, Right(p), Left(ones)) | (BinOp::BitAnd, Left(ones), Right(p)) if ones == layout.size.truncate(u128::MAX) @@ -1023,10 +1020,21 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { p } // Absorbing elements. - (BinOp::Mul | BinOp::BitAnd, _, Left(0)) + ( + BinOp::Mul | BinOp::MulWithOverflow | BinOp::MulUnchecked | BinOp::BitAnd, + _, + Left(0), + ) | (BinOp::Rem, _, Left(1)) | ( - BinOp::Mul | BinOp::Div | BinOp::Rem | BinOp::BitAnd | BinOp::Shl | BinOp::Shr, + BinOp::Mul + | BinOp::MulWithOverflow + | BinOp::MulUnchecked + | BinOp::Div + | BinOp::Rem + | BinOp::BitAnd + | BinOp::Shl + | BinOp::Shr, Left(0), _, ) => self.insert_scalar(Scalar::from_uint(0u128, layout.size), lhs_ty), @@ -1038,7 +1046,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { self.insert_scalar(Scalar::from_uint(ones, layout.size), lhs_ty) } // Sub/Xor with itself. - (BinOp::Sub | BinOp::BitXor, a, b) if a == b => { + (BinOp::Sub | BinOp::SubWithOverflow | BinOp::SubUnchecked | BinOp::BitXor, a, b) + if a == b => + { self.insert_scalar(Scalar::from_uint(0u128, layout.size), lhs_ty) } // Comparison: @@ -1052,7 +1062,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { _ => return None, }; - if checked { + if op.is_overflowing() { let false_val = self.insert_bool(false); Some(self.insert_tuple(vec![result, false_val])) } else {