Implement generic mad_sat

v2: Fix trailing whitespace
    Fix signed long overflow
    improve comment

v3: fix typo

Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
Reviewed-by: Tom Stellard <tom@stellard.net>
llvm-svn: 216923

6 files changed, 100 insertions, 0 deletions

diff --git a/libclc/generic/include/clc/clc.h b/libclc/generic/include/clc/clc.h
index 84b25ac77f0..20664f9b414 100644
--- a/libclc/generic/include/clc/clc.h
+++ b/libclc/generic/include/clc/clc.h
@@ -82,6 +82,7 @@
 #include <clc/integer/hadd.h>
 #include <clc/integer/mad24.h>
 #include <clc/integer/mad_hi.h>
+#include <clc/integer/mad_sat.h>
 #include <clc/integer/mul24.h>
 #include <clc/integer/mul_hi.h>
 #include <clc/integer/rhadd.h>
diff --git a/libclc/generic/include/clc/integer/mad_sat.h b/libclc/generic/include/clc/integer/mad_sat.h
new file mode 100644
index 00000000000..3e92372a27d
--- /dev/null
+++ b/libclc/generic/include/clc/integer/mad_sat.h
@@ -0,0 +1,3 @@
+#define __CLC_BODY <clc/integer/mad_sat.inc>
+#include <clc/integer/gentype.inc>
+#undef __CLC_BODY
diff --git a/libclc/generic/include/clc/integer/mad_sat.inc b/libclc/generic/include/clc/integer/mad_sat.inc
new file mode 100644
index 00000000000..5da2bdf8908
--- /dev/null
+++ b/libclc/generic/include/clc/integer/mad_sat.inc
@@ -0,0 +1 @@
+_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE mad_sat(__CLC_GENTYPE x, __CLC_GENTYPE y, __CLC_GENTYPE z);
diff --git a/libclc/generic/lib/SOURCES b/libclc/generic/lib/SOURCES
index 21fc7ca796a..5ad823dd1fd 100644
--- a/libclc/generic/lib/SOURCES
+++ b/libclc/generic/lib/SOURCES
@@ -20,6 +20,7 @@ integer/clz_if.ll
 integer/clz_impl.ll
 integer/hadd.cl
 integer/mad24.cl
+integer/mad_sat.cl
 integer/mul24.cl
 integer/mul_hi.cl
 integer/rhadd.cl
diff --git a/libclc/generic/lib/clcmacro.h b/libclc/generic/lib/clcmacro.h
index 730073ae1f9..ef102ea54e9 100644
--- a/libclc/generic/lib/clcmacro.h
+++ b/libclc/generic/lib/clcmacro.h
@@ -41,6 +41,28 @@
     return (RET_TYPE##16)(FUNCTION(x.lo, y.lo), FUNCTION(x.hi, y.hi)); \
   }
 
+#define _CLC_TERNARY_VECTORIZE(DECLSPEC, RET_TYPE, FUNCTION, ARG1_TYPE, ARG2_TYPE, ARG3_TYPE) \
+  DECLSPEC RET_TYPE##2 FUNCTION(ARG1_TYPE##2 x, ARG2_TYPE##2 y, ARG3_TYPE##2 z) { \
+    return (RET_TYPE##2)(FUNCTION(x.x, y.x, z.x), FUNCTION(x.y, y.y, z.y)); \
+  } \
+\
+  DECLSPEC RET_TYPE##3 FUNCTION(ARG1_TYPE##3 x, ARG2_TYPE##3 y, ARG3_TYPE##3 z) { \
+    return (RET_TYPE##3)(FUNCTION(x.x, y.x, z.x), FUNCTION(x.y, y.y, z.y), \
+                         FUNCTION(x.z, y.z, z.z)); \
+  } \
+\
+  DECLSPEC RET_TYPE##4 FUNCTION(ARG1_TYPE##4 x, ARG2_TYPE##4 y, ARG3_TYPE##4 z) { \
+    return (RET_TYPE##4)(FUNCTION(x.lo, y.lo, z.lo), FUNCTION(x.hi, y.hi, z.hi)); \
+  } \
+\
+  DECLSPEC RET_TYPE##8 FUNCTION(ARG1_TYPE##8 x, ARG2_TYPE##8 y, ARG3_TYPE##8 z) { \
+    return (RET_TYPE##8)(FUNCTION(x.lo, y.lo, z.lo), FUNCTION(x.hi, y.hi, z.hi)); \
+  } \
+\
+  DECLSPEC RET_TYPE##16 FUNCTION(ARG1_TYPE##16 x, ARG2_TYPE##16 y, ARG3_TYPE##16 z) { \
+    return (RET_TYPE##16)(FUNCTION(x.lo, y.lo, z.lo), FUNCTION(x.hi, y.hi, z.hi)); \
+  }
+
 #define _CLC_DEFINE_BINARY_BUILTIN(RET_TYPE, FUNCTION, BUILTIN, ARG1_TYPE, ARG2_TYPE) \
 _CLC_DEF _CLC_OVERLOAD RET_TYPE FUNCTION(ARG1_TYPE x, ARG2_TYPE y) { \
   return BUILTIN(x, y); \
diff --git a/libclc/generic/lib/integer/mad_sat.cl b/libclc/generic/lib/integer/mad_sat.cl
new file mode 100644
index 00000000000..1708b29efff
--- /dev/null
+++ b/libclc/generic/lib/integer/mad_sat.cl
@@ -0,0 +1,72 @@
+#include <clc/clc.h>
+#include "../clcmacro.h"
+
+_CLC_OVERLOAD _CLC_DEF char mad_sat(char x, char y, char z) {
+  return clamp((short)mad24((short)x, (short)y, (short)z), (short)CHAR_MIN, (short) CHAR_MAX);
+}
+
+_CLC_OVERLOAD _CLC_DEF uchar mad_sat(uchar x, uchar y, uchar z) {
+  return clamp((ushort)mad24((ushort)x, (ushort)y, (ushort)z), (ushort)0, (ushort) UCHAR_MAX);
+}
+
+_CLC_OVERLOAD _CLC_DEF short mad_sat(short x, short y, short z) {
+  return clamp((int)mad24((int)x, (int)y, (int)z), (int)SHRT_MIN, (int) SHRT_MAX);
+}
+
+_CLC_OVERLOAD _CLC_DEF ushort mad_sat(ushort x, ushort y, ushort z) {
+  return clamp((uint)mad24((uint)x, (uint)y, (uint)z), (uint)0, (uint) USHRT_MAX);
+}
+
+_CLC_OVERLOAD _CLC_DEF int mad_sat(int x, int y, int z) {
+  int mhi = mul_hi(x, y);
+  uint mlo = x * y;
+  long m = upsample(mhi, mlo);
+  m += z;
+  if (m > INT_MAX)
+    return INT_MAX;
+  if (m < INT_MIN)
+    return INT_MIN;
+  return m;
+}
+
+_CLC_OVERLOAD _CLC_DEF uint mad_sat(uint x, uint y, uint z) {
+  if (mul_hi(x, y) != 0)
+    return UINT_MAX;
+  return add_sat(x * y, z);
+}
+
+_CLC_OVERLOAD _CLC_DEF long mad_sat(long x, long y, long z) {
+  long hi = mul_hi(x, y);
+  ulong ulo = x * y;
+  long  slo = x * y;
+  /* Big overflow of more than 2 bits, add can't fix this */
+  if (((x < 0) == (y < 0)) && hi != 0)
+    return LONG_MAX;
+  /* Low overflow in mul and z not neg enough to correct it */
+  if (hi == 0 && ulo >= LONG_MAX && (z > 0 || (ulo + z) > LONG_MAX))
+    return LONG_MAX;
+  /* Big overflow of more than 2 bits, add can't fix this */
+  if (((x < 0) != (y < 0)) && hi != -1)
+    return LONG_MIN;
+  /* Low overflow in mul and z not pos enough to correct it */
+  if (hi == -1 && ulo <= ((ulong)LONG_MAX + 1UL) && (z < 0 || z < (LONG_MAX - ulo)))
+    return LONG_MIN;
+  /* We have checked all conditions, any overflow in addition returns
+   * the correct value */
+  return ulo + z;
+}
+
+_CLC_OVERLOAD _CLC_DEF ulong mad_sat(ulong x, ulong y, ulong z) {
+  if (mul_hi(x, y) != 0)
+    return ULONG_MAX;
+  return add_sat(x * y, z);
+}
+
+_CLC_TERNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, char, mad_sat, char, char, char)
+_CLC_TERNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, uchar, mad_sat, uchar, uchar, uchar)
+_CLC_TERNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, short, mad_sat, short, short, short)
+_CLC_TERNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, ushort, mad_sat, ushort, ushort, ushort)
+_CLC_TERNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, int, mad_sat, int, int, int)
+_CLC_TERNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, uint, mad_sat, uint, uint, uint)
+_CLC_TERNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, long, mad_sat, long, long, long)
+_CLC_TERNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, ulong, mad_sat, ulong, ulong, ulong)