File: mul_by_const.cpp

package info (click to toggle)
swiftlang 6.1.3-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 2,791,532 kB
  • sloc: cpp: 9,901,743; ansic: 2,201,431; asm: 1,091,827; python: 308,252; objc: 82,166; f90: 80,126; lisp: 38,358; pascal: 25,559; sh: 20,429; ml: 5,058; perl: 4,745; makefile: 4,484; awk: 3,535; javascript: 3,018; xml: 918; fortran: 664; cs: 573; ruby: 396
file content (27 lines) | stat: -rw-r--r-- 631 bytes parent folder | download | duplicates (42) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
 
// RUN: %clangxx_msan -O2 %s -o %t && %run %t

#include <sanitizer/msan_interface.h>

struct S {
  S(int a0) : a(a0) {}
  int a;
  int b;
};

// Here S is passed to FooRun as a 64-bit integer.
// This triggers an optimization where 10000 * s.a is transformed into
// ((*(uint64_t *)&s) * (10000 * 2**32)) >> 32
// Test that MSan understands that this kills the uninitialized high half of S
// (i.e. S::b).
void FooRun(S s) {
  int64_t x = 10000 * s.a;
  __msan_check_mem_is_initialized(&x, sizeof(x));
}

int main(void) {
  S z(1);
  // Take &z to ensure that it is built on stack.
  S *volatile p = &z;
  FooRun(z);
  return 0;
}