From 5c211bf969a6ae6b549d0a53daf4c99870c82210 Mon Sep 17 00:00:00 2001 From: Martin Nowack Date: Sun, 30 Aug 2015 01:47:20 +0200 Subject: Fix signed division by constant 1/ -1 Division by constant divisor get optimized using shift and multiplication operations in STP builder. The used method cannot be applied for divisor 1 and -1. In that case use slow path. --- test/regression/2015-08-30-sdiv-1.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 test/regression/2015-08-30-sdiv-1.c (limited to 'test/regression/2015-08-30-sdiv-1.c') diff --git a/test/regression/2015-08-30-sdiv-1.c b/test/regression/2015-08-30-sdiv-1.c new file mode 100644 index 00000000..a90df308 --- /dev/null +++ b/test/regression/2015-08-30-sdiv-1.c @@ -0,0 +1,19 @@ +// RUN: %llvmgcc %s -emit-llvm -g -O0 -c -o %t.bc +// RUN: rm -rf %t.klee-out +// RUN: %klee --output-dir=%t.klee-out -exit-on-error -solver-optimize-divides=true %t.bc +// RUN: rm -rf %t.klee-out +// RUN: %klee --output-dir=%t.klee-out -exit-on-error -solver-optimize-divides=false %t.bc + +/* Division by constant can be optimized.using mul/shift + * For signed division, div by 1 or -1 cannot be optimized like that. + */ +#include +int main() { + int32_t dividend; + klee_make_symbolic(÷nd, sizeof dividend, "Dividend"); + if ((3 ^ (dividend & 2)) / 1) + return 1; + if ((3 ^ (dividend & 2)) / -1) + return 1; + return 0; +} -- cgit 1.4.1