math: Add logb builtin

Ported from the amd-builtins branch.

Signed-off-by: Aaron Watry <awatry@gmail.com>
Reviewed-by: Matt Arsenault <Matthew.Arsenault@amd.com>
CC: Tom Stellard <thomas.stellard@amd.com>
llvm-svn: 292335

5 files changed, 36 insertions, 0 deletions

diff --git a/libclc/generic/include/clc/clc.h b/libclc/generic/include/clc/clc.h
index f95d7a75c15..024bf273184 100644
--- a/libclc/generic/include/clc/clc.h
+++ b/libclc/generic/include/clc/clc.h
@@ -76,6 +76,7 @@
 #include <clc/math/log10.h>
 #include <clc/math/log1p.h>
 #include <clc/math/log2.h>
+#include <clc/math/logb.h>
 #include <clc/math/mad.h>
 #include <clc/math/modf.h>
 #include <clc/math/nextafter.h>
diff --git a/libclc/generic/include/clc/math/logb.h b/libclc/generic/include/clc/math/logb.h
new file mode 100644
index 00000000000..8bdbdc34208
--- /dev/null
+++ b/libclc/generic/include/clc/math/logb.h
@@ -0,0 +1,2 @@
+#define __CLC_BODY <clc/math/logb.inc>
+#include <clc/math/gentype.inc>
diff --git a/libclc/generic/include/clc/math/logb.inc b/libclc/generic/include/clc/math/logb.inc
new file mode 100644
index 00000000000..059d2e016c0
--- /dev/null
+++ b/libclc/generic/include/clc/math/logb.inc
@@ -0,0 +1 @@
+_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE logb(__CLC_GENTYPE a);
diff --git a/libclc/generic/lib/SOURCES b/libclc/generic/lib/SOURCES
index 74bea25bbc2..517daba0ba3 100644
--- a/libclc/generic/lib/SOURCES
+++ b/libclc/generic/lib/SOURCES
@@ -104,6 +104,7 @@ math/log.cl
 math/log10.cl
 math/log1p.cl
 math/log2.cl
+math/logb.cl
 math/mad.cl
 math/modf.cl
 math/native_log.cl
diff --git a/libclc/generic/lib/math/logb.cl b/libclc/generic/lib/math/logb.cl
new file mode 100644
index 00000000000..31e51616534
--- /dev/null
+++ b/libclc/generic/lib/math/logb.cl
@@ -0,0 +1,31 @@
+#include <clc/clc.h>
+#include "math.h"
+#include "../clcmacro.h"
+
+_CLC_OVERLOAD _CLC_DEF float logb(float x) {
+    int ax = as_int(x) & EXSIGNBIT_SP32;
+    float s = -118 - clz(ax);
+    float r = (ax >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32;
+    r = ax >= PINFBITPATT_SP32 ? as_float(ax) : r;
+    r = ax < 0x00800000 ? s : r;
+    r = ax == 0 ? as_float(NINFBITPATT_SP32) : r;
+    return r;
+}
+
+_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, logb, float);
+
+#ifdef cl_khr_fp64
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+
+_CLC_OVERLOAD _CLC_DEF double logb(double x) {
+    long ax = as_long(x) & EXSIGNBIT_DP64;
+    double s = -1011L - clz(ax);
+    double r = (int) (ax >> EXPSHIFTBITS_DP64) - EXPBIAS_DP64;
+    r = ax >= PINFBITPATT_DP64 ? as_double(ax) : r;
+    r = ax < 0x0010000000000000L ? s : r;
+    r = ax == 0L ? as_double(NINFBITPATT_DP64) : r;
+    return r;
+}
+
+_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, logb, double)
+#endif