[Libclc-dev] [PATCH] integer: Update integer limits to comply with spec

Aaron Watry via Libclc-dev libclc-dev at lists.llvm.org
Fri Sep 11 17:31:17 PDT 2015

The values for the char/short/integer/long minimums were declared with
their actual values, not the definitions from the CL spec (v1.1).  As
a result, (-2147483648) was actually being treated as a long by the
compiler, not an int, which caused issues when trying to add/subtract
that value from a vector.

Update the definitions to use the values declared by the spec, and also
add explicit casts for the char/short/int minimums so that the compiler
actually treats them as shorts/chars. Without those casts, they
actually end up stored as integers, and the compiler may end up storing
the INT_MIN as a long.

The compiler can sign extend the values if it needs to convert the
char->short, short->int, or int->long

v2: Add explicit cast for INT_MIN and fix some type-o's and wrapping
    in the commit message.

Reported-by: Moritz Pflanzer <moritz.pflanzer14 at imperial.ac.uk>
CC: Moritz Pflanzer <moritz.pflanzer14 at imperial.ac.uk>
CC: Tom Stellard <thomas.stellard at amd.com>
Signed-off-by: Aaron Watry <awatry at gmail.com>
 generic/include/clc/integer/definitions.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/generic/include/clc/integer/definitions.h b/generic/include/clc/integer/definitions.h
index a407974..89de232 100644
--- a/generic/include/clc/integer/definitions.h
+++ b/generic/include/clc/integer/definitions.h
@@ -1,14 +1,14 @@
 #define CHAR_BIT 8
 #define INT_MAX 2147483647
-#define INT_MIN -2147483648
+#define INT_MIN ((int)(-2147483647 - 1))
 #define LONG_MAX  0x7fffffffffffffffL
-#define LONG_MIN -0x8000000000000000L
+#define LONG_MIN (-0x7fffffffffffffffL - 1)
 #define SCHAR_MAX 127
-#define SCHAR_MIN -128
-#define CHAR_MAX 127
-#define CHAR_MIN -128
+#define SCHAR_MIN ((char)(-127 - 1))
 #define SHRT_MAX 32767
-#define SHRT_MIN -32768
+#define SHRT_MIN ((short)(-32767 - 1))
 #define UCHAR_MAX 255
 #define USHRT_MAX 65535
 #define UINT_MAX 0xffffffff

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