diff options
Diffstat (limited to 'lib/compiler/src/beam_ssa.hrl')
| -rw-r--r-- | lib/compiler/src/beam_ssa.hrl | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/lib/compiler/src/beam_ssa.hrl b/lib/compiler/src/beam_ssa.hrl index fa76b08453..509a94135e 100644 --- a/lib/compiler/src/beam_ssa.hrl +++ b/lib/compiler/src/beam_ssa.hrl @@ -62,5 +62,13 @@ -record(b_local, {name :: beam_ssa:b_literal(), arity :: non_neg_integer()}). -%% If this block exists, it calls erlang:error(badarg). --define(BADARG_BLOCK, 1). +%% This is a psuedo-block used to express that certain instructions and BIFs +%% throw exceptions on failure. The code generator rewrites all branches to +%% this block to {f,0} which causes the instruction to throw an exception +%% instead of branching. +%% +%% Since this is not an ordinary block, it's illegal to merge it with other +%% blocks, and jumps are only valid when we know that an exception will be +%% thrown by the operation that branches here; the *block itself* does not +%% throw an exception. +-define(EXCEPTION_BLOCK, 1). |