From e0124fa82fba000412856476f97d078fba37c5e2 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Thu, 26 Jul 2018 11:09:11 -0700 Subject: [PATCH] Rename local variables to clarify their purpose. --- lib/codegen/src/legalizer/heap.rs | 34 +++++++++++++++---------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/lib/codegen/src/legalizer/heap.rs b/lib/codegen/src/legalizer/heap.rs index fdf3fdb094..122474c63e 100644 --- a/lib/codegen/src/legalizer/heap.rs +++ b/lib/codegen/src/legalizer/heap.rs @@ -17,7 +17,7 @@ pub fn expand_heap_addr( _isa: &TargetIsa, ) { // Unpack the instruction. - let (heap, offset, size) = match func.dfg[inst] { + let (heap, offset, access_size) = match func.dfg[inst] { ir::InstructionData::HeapAddr { opcode, heap, @@ -32,10 +32,10 @@ pub fn expand_heap_addr( match func.heaps[heap].style { ir::HeapStyle::Dynamic { bound_gv } => { - dynamic_addr(inst, heap, offset, size, bound_gv, func) + dynamic_addr(inst, heap, offset, access_size, bound_gv, func) } ir::HeapStyle::Static { bound } => { - static_addr(inst, heap, offset, size, bound.into(), func, cfg) + static_addr(inst, heap, offset, access_size, bound.into(), func, cfg) } } } @@ -45,34 +45,34 @@ fn dynamic_addr( inst: ir::Inst, heap: ir::Heap, offset: ir::Value, - size: u32, + access_size: u32, bound_gv: ir::GlobalValue, func: &mut ir::Function, ) { - let size = i64::from(size); + let access_size = i64::from(access_size); let offset_ty = func.dfg.value_type(offset); let addr_ty = func.dfg.value_type(func.dfg.first_result(inst)); let min_size = func.heaps[heap].min_size.into(); let mut pos = FuncCursor::new(func).at_inst(inst); pos.use_srcloc(inst); - // Start with the bounds check. Trap if `offset + size > bound`. + // Start with the bounds check. Trap if `offset + access_size > bound`. let bound = pos.ins().global_value(addr_ty, bound_gv); let oob; - if size == 1 { + if access_size == 1 { // `offset > bound - 1` is the same as `offset >= bound`. oob = pos.ins() .icmp(IntCC::UnsignedGreaterThanOrEqual, offset, bound); - } else if size <= min_size { - // We know that bound >= min_size, so here we can compare `offset > bound - size` without + } else if access_size <= min_size { + // We know that bound >= min_size, so here we can compare `offset > bound - access_size` without // wrapping. - let adj_bound = pos.ins().iadd_imm(bound, -size); + let adj_bound = pos.ins().iadd_imm(bound, -access_size); oob = pos.ins() .icmp(IntCC::UnsignedGreaterThan, offset, adj_bound); } else { // We need an overflow check for the adjusted offset. - let size_val = pos.ins().iconst(offset_ty, size); - let (adj_offset, overflow) = pos.ins().iadd_cout(offset, size_val); + let access_size_val = pos.ins().iconst(offset_ty, access_size); + let (adj_offset, overflow) = pos.ins().iadd_cout(offset, access_size_val); pos.ins().trapnz(overflow, ir::TrapCode::HeapOutOfBounds); oob = pos.ins() .icmp(IntCC::UnsignedGreaterThan, adj_offset, bound); @@ -87,19 +87,19 @@ fn static_addr( inst: ir::Inst, heap: ir::Heap, offset: ir::Value, - size: u32, + access_size: u32, bound: i64, func: &mut ir::Function, cfg: &mut ControlFlowGraph, ) { - let size = i64::from(size); + let access_size = i64::from(access_size); let offset_ty = func.dfg.value_type(offset); let addr_ty = func.dfg.value_type(func.dfg.first_result(inst)); let mut pos = FuncCursor::new(func).at_inst(inst); pos.use_srcloc(inst); - // Start with the bounds check. Trap if `offset + size > bound`. - if size > bound { + // Start with the bounds check. Trap if `offset + access_size > bound`. + if access_size > bound { // This will simply always trap since `offset >= 0`. pos.ins().trap(ir::TrapCode::HeapOutOfBounds); pos.func.dfg.replace(inst).iconst(addr_ty, 0); @@ -114,7 +114,7 @@ fn static_addr( } // Check `offset > limit` which is now known non-negative. - let limit = bound - size; + let limit = bound - access_size; // We may be able to omit the check entirely for 32-bit offsets if the heap bound is 4 GB or // more.