diff options
Diffstat (limited to 'lib/hipe/test/basic_SUITE_data/basic_strength_reduce.erl')
-rw-r--r-- | lib/hipe/test/basic_SUITE_data/basic_strength_reduce.erl | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/lib/hipe/test/basic_SUITE_data/basic_strength_reduce.erl b/lib/hipe/test/basic_SUITE_data/basic_strength_reduce.erl new file mode 100644 index 0000000000..0f94320a33 --- /dev/null +++ b/lib/hipe/test/basic_SUITE_data/basic_strength_reduce.erl @@ -0,0 +1,65 @@ +%%% -*- erlang-indent-level: 2 -*- +%%%------------------------------------------------------------------- +%%% Author: Kostis Sagonas +%%% +%%% Tests the strength reduction component of the HiPE compiler. +%%%------------------------------------------------------------------- +-module(basic_strength_reduce). + +-export([test/0]). +%% These functions are exported so as to not remove them by inlining +-export([crash_0/1, crash_1/1, crash_2/1, crash_3/1, bug_div_2N/1]). + +test() -> + ok = test_strength_reduce1(), + ok. + +%%-------------------------------------------------------------------- + +test_strength_reduce1() -> + ok = crash_0(0), + ok = crash_1(42), + ok = crash_2(42), + ok = crash_3(42), + 5 = 42 bsr 3 = bug_div_2N(42), + -6 = -42 bsr 3 = bug_div_2N(-42) - 1, + ok. + +%% This is a crash report by Peter Wang (10 July 2007) triggering an +%% R11B-5 crash: strength reduction could not handle calls with no +%% destination +crash_0(A) -> + case A of + 0 -> + A div 8, + ok + end. + +%% The above was simplified to the following which showed another +%% crash, this time on RTL +crash_1(A) when is_integer(A), A >= 0 -> + A div 8, + ok. + +%% A similar crash like the first one, but in a different place in the +%% code, was triggered by the following code +crash_2(A) when is_integer(A), A >= 0 -> + A div 1, + ok. + +%% A crash similar to the first one happened in the following code +crash_3(A) -> + case A of + 42 -> + A * 0, + ok + end. + +%% Strength reduction for div/2 and rem/2 with a power of 2 +%% should be performed only for non-negative integers +bug_div_2N(X) when is_integer(X), X >= 0 -> + X div 8; +bug_div_2N(X) when is_integer(X), X < 0 -> + X div 8. + +%%-------------------------------------------------------------------- |