This is an old patch I had around.
Vector selects seem to work well from LLVM 3.4. Using them might
improve code quality, as it might make constant propagation pass more
effective.
Tested lp_test_*
---
src/gallium/auxiliary/gallivm/lp_bld_logic.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_logic.c
b/src/gallium/auxiliary/gallivm/lp_bld_logic.c
index 19d30d0..b3694ea 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_logic.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_logic.c
@@ -314,11 +314,13 @@ lp_build_select(struct lp_build_context *bld,
mask = LLVMBuildTrunc(builder, mask, LLVMInt1TypeInContext(lc), "");
res = LLVMBuildSelect(builder, mask, a, b, "");
}
- else if (0) {
+ else if (HAVE_LLVM >= 0x0304) {
/* Generate a vector select.
*
- * XXX: Using vector selects would avoid emitting intrinsics, but they
aren't
- * properly supported yet.
+ * Using vector selects would avoid emitting intrinsics, but they weren't
+ * properly supported yet for a long time.
+ *
+ * LLVM 3.4 appears to reliably support it.
*
* LLVM 3.1 supports it, but it yields buggy code (e.g. lp_blend_test).
*
--
2.5.0
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