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Fix missing modification of jump table in licm

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This commit is contained in:
Y-Nak
2020-05-14 22:20:24 +09:00
committed by Yoshitomo Nakanishi
parent 2cec20aa57
commit 855a6374dd
5 changed files with 109 additions and 21 deletions
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37
cranelift/codegen/src/licm.rs
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@@ -61,8 +61,8 @@ pub fn do_licm(
domtree.compute(func, cfg);
}
// Insert a pre-header before the header, modifying the function layout and CFG to reflect it.
// A jump instruction to the header is placed at the end of the pre-header.
/// Insert a pre-header before the header, modifying the function layout and CFG to reflect it.
/// A jump instruction to the header is placed at the end of the pre-header.
fn create_pre_header(
isa: &dyn TargetIsa,
header: Block,
@@ -81,30 +81,31 @@ fn create_pre_header(
for typ in header_args_types {
pre_header_args_value.push(func.dfg.append_block_param(pre_header, typ), pool);
}
for BlockPredecessor {
inst: last_inst, ..
} in cfg.pred_iter(header)
{
// We only follow normal edges (not the back edges)
if !domtree.dominates(header, last_inst, &func.layout) {
func.change_branch_destination(last_inst, pre_header);
func.rewrite_branch_destination(last_inst, header, pre_header);
}
}
{
let mut pos = EncCursor::new(func, isa).at_top(header);
// Inserts the pre-header at the right place in the layout.
pos.insert_block(pre_header);
pos.next_inst();
pos.ins().jump(header, pre_header_args_value.as_slice(pool));
}
// Inserts the pre-header at the right place in the layout.
let mut pos = EncCursor::new(func, isa).at_top(header);
pos.insert_block(pre_header);
pos.next_inst();
pos.ins().jump(header, pre_header_args_value.as_slice(pool));
pre_header
}
// Detects if a loop header has a natural pre-header.
//
// A loop header has a pre-header if there is only one predecessor that the header doesn't
// dominate.
// Returns the pre-header Block and the instruction jumping to the header.
/// Detects if a loop header has a natural pre-header.
///
/// A loop header has a pre-header if there is only one predecessor that the header doesn't
/// dominate.
/// Returns the pre-header Block and the instruction jumping to the header.
fn has_pre_header(
layout: &Layout,
cfg: &ControlFlowGraph,
@@ -176,9 +177,9 @@ fn is_loop_invariant(inst: Inst, dfg: &DataFlowGraph, loop_values: &FxHashSet<Va
true
}
// Traverses a loop in reverse post-order from a header block and identify loop-invariant
// instructions. These loop-invariant instructions are then removed from the code and returned
// (in reverse post-order) for later use.
/// Traverses a loop in reverse post-order from a header block and identify loop-invariant
/// instructions. These loop-invariant instructions are then removed from the code and returned
/// (in reverse post-order) for later use.
fn remove_loop_invariant_instructions(
lp: Loop,
func: &mut Function,