ASLR introduces non-determinism

[bmwiedemann]

While working on reproducible builds for openSUSE, I found that
our intel-graphics-compiler v2.5.6 varies between builds.

My tools show, that variations go away when I disable Address-Space-Layour-Randomization(ASLR) during the build.

Two source files differed thus:

/home/abuild/rpmbuild/BUILD/build/IGC/Release/bif/embedder/OCLBiFImpl__igc_bif_BIFBC_122.cpp
@@ -2,49 +2,49 @@
 
 unsigned char __attribute__((visibility("default"))) _igc_bif_BIFBC_122[] = {
         0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x78, 0x03, 0x00, 0x00,
-        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x57, 0x56, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-        0x8c, 0x4e, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x57, 0x56, 0x00, 0x00, 0x8c, 0x4e, 0x04, 0x00,
-        0x00, 0x00, 0x00, 0x00, 0x34, 0x54, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x57, 0x56, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xd7, 0x55, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x8c, 0x4e, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0xd7, 0x55, 0x00, 0x00, 0x8c, 0x4e, 0x04, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x34, 0x54, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0xd7, 0x55, 0x00, 0x00,
...

/home/abuild/rpmbuild/BUILD/build/IGC/VectorCompiler/lib/BiF/VCBuiltins64.cpp
@@ -3,65 +3,65 @@
 #include "IGC/common/StringMacros.hpp"
 #include "llvm/ADT/StringRef.h"

-static unsigned char VCBuiltins64RawDataPLTF0[] = { 0x42, 0x43, 0xC0, 0xDE, 0x35, 0x14, 0x0, 0x0, 0x5, 0x0, 0x0, 0x0, 0x62, 0xC, 0x30, 0x24, 0x4A, 0x59, 0xBE, 0x66, 0x8D, 0xFB, 0xB4, 0x9F, 0xB, 0x51, 0x80, 0x4C, 0x1, 0x0, 0x0,...
+static unsigned char VCBuiltins64RawDataPLTF0[] = { 0x42, 0x43, 0xC0, 0xDE, 0x35, 0x14, 0x0, 0x0, 0x5, 0x0, 0x0, 0x0, 0x62, 0xC, 0x30, 0x24, 0x4A, 0x59, 0xBE, 0x66, 0x8D, 0xFB, 0xB4, 0x9F, 0xB, 0x51, 0x80, 0x4C, 0x1, 0x0, 0x0,...
[... more similar diffs here ...]

See https://github.com/bmwiedemann/theunreproduciblepackage/tree/master/aslr for examples of how ASLR can add non-determinism.