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Don't special-case br_table with an empty table.

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Empty br_table tables are very uncommon (they're easy for wasm producers to
optimize away), so we don't need to special-case them.
This commit is contained in:
Dan Gohman
2017-08-30 09:21:58 -07:00
parent 4ccd21ba94
commit a0a3401ef1
1 changed files with 36 additions and 46 deletions
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10
lib/wasm/src/code_translator.rs
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@@ -523,7 +523,6 @@ fn translate_operator(op: &Operator,
if jump_args_count == 0 { if jump_args_count == 0 {
// No jump arguments // No jump arguments
let val = stack.pop().unwrap(); let val = stack.pop().unwrap();
if depths.len() > 0 {
let jt = builder.create_jump_table(); let jt = builder.create_jump_table();
for (index, depth) in depths.iter().enumerate() { for (index, depth) in depths.iter().enumerate() {
let i = control_stack.len() - 1 - (*depth as usize); let i = control_stack.len() - 1 - (*depth as usize);
@@ -533,7 +532,6 @@ fn translate_operator(op: &Operator,
frame.set_reachable(); frame.set_reachable();
} }
builder.ins().br_table(val, jt); builder.ins().br_table(val, jt);
}
let i = control_stack.len() - 1 - (default as usize); let i = control_stack.len() - 1 - (default as usize);
let frame = &mut control_stack[i]; let frame = &mut control_stack[i];
let ebb = frame.br_destination(); let ebb = frame.br_destination();
@@ -546,7 +544,6 @@ fn translate_operator(op: &Operator,
let val = stack.pop().unwrap(); let val = stack.pop().unwrap();
let cut_index = stack.len() - jump_args_count; let cut_index = stack.len() - jump_args_count;
let jump_args = stack.split_off(cut_index); let jump_args = stack.split_off(cut_index);
if depths.len() > 0 {
let jt = builder.create_jump_table(); let jt = builder.create_jump_table();
let dest_ebbs: HashMap<usize, Ebb> = depths let dest_ebbs: HashMap<usize, Ebb> = depths
.iter() .iter()
@@ -577,13 +574,6 @@ fn translate_operator(op: &Operator,
frame.set_reachable(); frame.set_reachable();
} }
state.real_unreachable_stack_depth = 1 + min_depth as usize; state.real_unreachable_stack_depth = 1 + min_depth as usize;
} else {
let ebb = control_stack[control_stack.len() - 1 - (default as usize)]
.br_destination();
builder.ins().jump(ebb, jump_args.as_slice());
stack.extend(jump_args);
state.real_unreachable_stack_depth = 1 + min_depth as usize;
}
} }
} }
Operator::Return => { Operator::Return => {