mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 22:02:23 +01:00
Richard Smith
583f5aa508
These can't be supported by `TryEvalInst`, because we don't track sufficient information about predecessors and branch conditions in SemIR to efficiently compute the constant result. Even if we could do so, we may not want to treat all `BlockArg`s for which we can infer a constant value as being constants. Instead, set the constant value explicitly after creating the corresponding `BlockArg` instruction.
77 lines
2.9 KiB
C++
77 lines
2.9 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
|
|
#include "toolchain/check/context.h"
|
|
#include "toolchain/check/convert.h"
|
|
|
|
namespace Carbon::Check {
|
|
|
|
auto HandleIfExprIf(Context& context, Parse::IfExprIfId node_id) -> bool {
|
|
// Alias node_id for if/then/else consistency.
|
|
auto& if_node = node_id;
|
|
|
|
auto [cond_node, cond_value_id] = context.node_stack().PopExprWithNodeId();
|
|
|
|
// Convert the condition to `bool`, and branch on it.
|
|
cond_value_id = ConvertToBoolValue(context, if_node, cond_value_id);
|
|
context.node_stack().Push(cond_node, cond_value_id);
|
|
auto then_block_id =
|
|
context.AddDominatedBlockAndBranchIf(if_node, cond_value_id);
|
|
auto else_block_id = context.AddDominatedBlockAndBranch(if_node);
|
|
|
|
// Start emitting the `then` block.
|
|
context.inst_block_stack().Pop();
|
|
context.inst_block_stack().Push(then_block_id);
|
|
context.AddCurrentCodeBlockToFunction(node_id);
|
|
|
|
context.node_stack().Push(if_node, else_block_id);
|
|
return true;
|
|
}
|
|
|
|
auto HandleIfExprThen(Context& context, Parse::IfExprThenId node_id) -> bool {
|
|
auto then_value_id = context.node_stack().PopExpr();
|
|
auto else_block_id = context.node_stack().Peek<Parse::NodeKind::IfExprIf>();
|
|
|
|
// Convert the first operand to a value.
|
|
then_value_id = ConvertToValueExpr(context, then_value_id);
|
|
|
|
// Start emitting the `else` block.
|
|
context.inst_block_stack().Push(else_block_id);
|
|
context.AddCurrentCodeBlockToFunction(node_id);
|
|
|
|
context.node_stack().Push(node_id, then_value_id);
|
|
return true;
|
|
}
|
|
|
|
auto HandleIfExprElse(Context& context, Parse::IfExprElseId node_id) -> bool {
|
|
// Alias node_id for if/then/else consistency.
|
|
auto& else_node = node_id;
|
|
|
|
auto else_value_id = context.node_stack().PopExpr();
|
|
auto then_value_id = context.node_stack().Pop<Parse::NodeKind::IfExprThen>();
|
|
auto [if_node, _] =
|
|
context.node_stack().PopWithNodeId<Parse::NodeKind::IfExprIf>();
|
|
auto cond_value_id = context.node_stack().PopExpr();
|
|
|
|
// Convert the `else` value to the `then` value's type, and finish the `else`
|
|
// block.
|
|
// TODO: Find a common type, and convert both operands to it instead.
|
|
auto result_type_id = context.insts().Get(then_value_id).type_id();
|
|
else_value_id =
|
|
ConvertToValueOfType(context, else_node, else_value_id, result_type_id);
|
|
|
|
// Create a resumption block and branches to it.
|
|
auto chosen_value_id = context.AddConvergenceBlockWithArgAndPush(
|
|
if_node, {else_value_id, then_value_id});
|
|
context.SetBlockArgResultBeforeConstantUse(chosen_value_id, cond_value_id,
|
|
then_value_id, else_value_id);
|
|
context.AddCurrentCodeBlockToFunction(node_id);
|
|
|
|
// Push the result value.
|
|
context.node_stack().Push(else_node, chosen_value_id);
|
|
return true;
|
|
}
|
|
|
|
} // namespace Carbon::Check
|