diff options
| -rw-r--r-- | test/libsolidity/GasMeter.cpp | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/test/libsolidity/GasMeter.cpp b/test/libsolidity/GasMeter.cpp index 0d66456c..f16d9abe 100644 --- a/test/libsolidity/GasMeter.cpp +++ b/test/libsolidity/GasMeter.cpp @@ -307,6 +307,46 @@ BOOST_AUTO_TEST_CASE(regular_functions_exclude_fallback) testCreationTimeGas(sourceCode); testRunTimeGas("x()", vector<bytes>{encodeArgs()}); } + +BOOST_AUTO_TEST_CASE(complex_control_flow) +{ + // This crashed the gas estimator previously (or took a very long time). + // Now we do not follow branches if they start out with lower gas costs than the ones + // we previously considered. This of course reduces accuracy. + char const* sourceCode = R"( + contract log { + function ln(int128 x) constant returns (int128 result) { + int128 t = x / 256; + int128 y = 5545177; + x = t; + t = x * 16; if (t <= 1000000) { x = t; y = y - 2772588; } + t = x * 4; if (t <= 1000000) { x = t; y = y - 1386294; } + t = x * 2; if (t <= 1000000) { x = t; y = y - 693147; } + t = x + x / 2; if (t <= 1000000) { x = t; y = y - 405465; } + t = x + x / 4; if (t <= 1000000) { x = t; y = y - 223144; } + t = x + x / 8; if (t <= 1000000) { x = t; y = y - 117783; } + t = x + x / 16; if (t <= 1000000) { x = t; y = y - 60624; } + t = x + x / 32; if (t <= 1000000) { x = t; y = y - 30771; } + t = x + x / 64; if (t <= 1000000) { x = t; y = y - 15504; } + t = x + x / 128; if (t <= 1000000) { x = t; y = y - 7782; } + t = x + x / 256; if (t <= 1000000) { x = t; y = y - 3898; } + t = x + x / 512; if (t <= 1000000) { x = t; y = y - 1951; } + t = x + x / 1024; if (t <= 1000000) { x = t; y = y - 976; } + t = x + x / 2048; if (t <= 1000000) { x = t; y = y - 488; } + t = x + x / 4096; if (t <= 1000000) { x = t; y = y - 244; } + t = x + x / 8192; if (t <= 1000000) { x = t; y = y - 122; } + t = x + x / 16384; if (t <= 1000000) { x = t; y = y - 61; } + t = x + x / 32768; if (t <= 1000000) { x = t; y = y - 31; } + t = x + x / 65536; if (t <= 1000000) { y = y - 15; } + return y; + } + } + )"; + testCreationTimeGas(sourceCode); + // max gas is used for small x + testRunTimeGas("ln(int128)", vector<bytes>{encodeArgs(0), encodeArgs(10), encodeArgs(105), encodeArgs(30000)}); +} + BOOST_AUTO_TEST_SUITE_END() } |