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authorJohn Högberg <[email protected]>2019-03-08 11:27:49 +0100
committerJohn Högberg <[email protected]>2019-03-08 13:05:54 +0100
commit32ae1b4404b200d4a033d34920e09854770be042 (patch)
tree19cfb9a5fa8cffd91b6df6945d8ff60108f6cef5 /lib/compiler/test/float_SUITE.erl
parent31bff2cdb13a6e2032b7f067d037da0520752fc0 (diff)
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beam_ssa_opt: Fix crash in ssa_opt_float
For reasons better explained in the source code, ssa_opt_float skips optimizing inside guards but it failed to do so consistently; while the pass never processed guard blocks, it was still possible to erroneously defer error checking to a guard block, crashing the compiler once it realized its state was invalid.
Diffstat (limited to 'lib/compiler/test/float_SUITE.erl')
-rw-r--r--lib/compiler/test/float_SUITE.erl23
1 files changed, 20 insertions, 3 deletions
diff --git a/lib/compiler/test/float_SUITE.erl b/lib/compiler/test/float_SUITE.erl
index 831e8279aa..0fa8070dc8 100644
--- a/lib/compiler/test/float_SUITE.erl
+++ b/lib/compiler/test/float_SUITE.erl
@@ -21,15 +21,16 @@
-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1,
init_per_group/2,end_per_group/2,
pending/1,bif_calls/1,math_functions/1,mixed_float_and_int/1,
- subtract_number_type/1]).
+ subtract_number_type/1,float_followed_by_guard/1]).
-include_lib("common_test/include/ct.hrl").
suite() -> [{ct_hooks,[ts_install_cth]}].
-all() ->
+all() ->
[pending, bif_calls, math_functions,
- mixed_float_and_int, subtract_number_type].
+ mixed_float_and_int, subtract_number_type,
+ float_followed_by_guard].
groups() ->
[].
@@ -187,5 +188,21 @@ fact(0, P) -> P;
fact(1, P) -> P;
fact(N, P) -> fact(N-1, P*N).
+float_followed_by_guard(Config) when is_list(Config) ->
+ true = ffbg_1(5, 1),
+ false = ffbg_1(1, 5),
+ ok.
+
+ffbg_1(A, B0) ->
+ %% This is a non-guard block followed by a *guard block* that starts with a
+ %% floating point operation, and the compiler erroneously assumed that it
+ %% was safe to skip fcheckerror because the next block started with a float
+ %% op.
+ B = id(B0) / 1.0,
+ if
+ A - B > 0.0 -> true;
+ A - B =< 0.0 -> false
+ end.
+
id(I) -> I.