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| author | Zack Rusin <zackr@vmware.com> | 2013-07-18 03:32:02 -0400 |
|---|---|---|
| committer | Zack Rusin <zackr@vmware.com> | 2013-07-19 16:29:18 -0400 |
| commit | f7c06785d08156320836ee94552e7f89e1542647 (patch) | |
| tree | 35d718c0112585aa719445fc179fe54e52e37858 /src/gallium/auxiliary/gallivm/lp_bld_arit.c | |
| parent | 018c69ac56ee0579b5d4f138340444b326c4e6dc (diff) | |
| download | external_mesa3d-f7c06785d08156320836ee94552e7f89e1542647.zip external_mesa3d-f7c06785d08156320836ee94552e7f89e1542647.tar.gz external_mesa3d-f7c06785d08156320836ee94552e7f89e1542647.tar.bz2 | |
gallivm: add a log function that handles edge cases
Same as log2_safe, which means that it can handle infs, 0s and
nans.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Diffstat (limited to 'src/gallium/auxiliary/gallivm/lp_bld_arit.c')
| -rw-r--r-- | src/gallium/auxiliary/gallivm/lp_bld_arit.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c index 2ce287f..98409c3 100644 --- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c +++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c @@ -3080,6 +3080,7 @@ lp_build_exp(struct lp_build_context *bld, /** * Generate log(x) + * Behavior is undefined with infs, 0s and nans */ LLVMValueRef lp_build_log(struct lp_build_context *bld, @@ -3094,6 +3095,22 @@ lp_build_log(struct lp_build_context *bld, return lp_build_mul(bld, log2, lp_build_log2(bld, x)); } +/** + * Generate log(x) that handles edge cases (infs, 0s and nans) + */ +LLVMValueRef +lp_build_log_safe(struct lp_build_context *bld, + LLVMValueRef x) +{ + /* log(2) */ + LLVMValueRef log2 = lp_build_const_vec(bld->gallivm, bld->type, + 0.69314718055994529); + + assert(lp_check_value(bld->type, x)); + + return lp_build_mul(bld, log2, lp_build_log2_safe(bld, x)); +} + /** * Generate polynomial. |