rootn: Use denormal path only
It's OK to either flush to 0 or return denormal result if the device
does not support denormals. See sec 7.2 and 7.5.3 of OCL specs
Use 0.0f explicitly intead of relying on GPU to flush it.
Fixes CTS on carrizo and turks
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
Acked-by: Aaron Watry <awatry@gmail.com>
Tested-by: Aaron Watry <awatry@gmail.com>
git-svn-id: https://llvm.org/svn/llvm-project/libclc/trunk@332324 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/generic/lib/math/clc_rootn.cl b/generic/lib/math/clc_rootn.cl
index d7ee185..0a2c98d 100644
--- a/generic/lib/math/clc_rootn.cl
+++ b/generic/lib/math/clc_rootn.cl
@@ -170,16 +170,7 @@
tv = USE_TABLE(exp_tbl_ep, j);
float expylogx = mad(tv.s0, poly, mad(tv.s1, poly, tv.s1)) + tv.s0;
- float sexpylogx;
- if (!__clc_fp32_subnormals_supported()) {
- int explg = ((as_uint(expylogx) & EXPBITS_SP32 >> 23) - 127);
- m = (23-(m + 149)) == 0 ? 1: m;
- uint mantissa = ((as_uint(expylogx) & MANTBITS_SP32)|IMPBIT_SP32) >> (23-(m + 149));
- sexpylogx = as_float(mantissa);
- } else {
- sexpylogx = expylogx * as_float(0x1 << (m + 149));
- }
-
+ float sexpylogx = __clc_fp32_subnormals_supported() ? expylogx * as_float(0x1 << (m + 149)) : 0.0f;
float texpylogx = as_float(as_int(expylogx) + m2);
expylogx = m < -125 ? sexpylogx : texpylogx;
