From dded2edf8bedb9a5bafd7788e52dc8e714527186 Mon Sep 17 00:00:00 2001 From: Roland Scheidegger Date: Wed, 17 Apr 2019 02:34:01 +0200 Subject: [PATCH] gallivm: fix saturated signed add / sub with llvm 9 llvm 8 removed saturated unsigned add / sub x86 sse2 intrinsics, and now llvm 9 removed the signed versions as well - they were proposed for removal earlier, but the pattern to recognize those was very complex, so it wasn't done then. However, instead of these arch-specific intrinsics, there's now arch-independent intrinsics for saturated add / sub, both for signed and unsigned, so use these. They should have only advantages (work with arbitrary vector sizes, optimal code for all archs), although I don't know how well they work in practice for other archs (at least for x86 they do the right thing). Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110454 Reviewed-by: Brian Paul --- src/gallium/auxiliary/gallivm/lp_bld_arit.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c index 057c50ed278..02fb81afe51 100644 --- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c +++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c @@ -555,6 +555,12 @@ lp_build_add(struct lp_build_context *bld, return bld->one; if (!type.floating && !type.fixed) { + if (HAVE_LLVM >= 0x0900) { + char intrin[32]; + intrinsic = type.sign ? "llvm.sadd.sat" : "llvm.uadd.sat"; + lp_format_intrinsic(intrin, sizeof intrin, intrinsic, bld->vec_type); + return lp_build_intrinsic_binary(builder, intrin, bld->vec_type, a, b); + } if (type.width * type.length == 128) { if (util_cpu_caps.has_sse2) { if (type.width == 8) @@ -625,6 +631,7 @@ lp_build_add(struct lp_build_context *bld, * NOTE: cmp/select does sext/trunc of the mask. Does not seem to * interfere with llvm's ability to recognize the pattern but seems * a bit brittle. + * NOTE: llvm 9+ always uses (non arch specific) intrinsic. */ LLVMValueRef overflowed = lp_build_cmp(bld, PIPE_FUNC_GREATER, a, res); res = lp_build_select(bld, overflowed, @@ -876,6 +883,12 @@ lp_build_sub(struct lp_build_context *bld, return bld->zero; if (!type.floating && !type.fixed) { + if (HAVE_LLVM >= 0x0900) { + char intrin[32]; + intrinsic = type.sign ? "llvm.ssub.sat" : "llvm.usub.sat"; + lp_format_intrinsic(intrin, sizeof intrin, intrinsic, bld->vec_type); + return lp_build_intrinsic_binary(builder, intrin, bld->vec_type, a, b); + } if (type.width * type.length == 128) { if (util_cpu_caps.has_sse2) { if (type.width == 8) @@ -925,6 +938,7 @@ lp_build_sub(struct lp_build_context *bld, * NOTE: cmp/select does sext/trunc of the mask. Does not seem to * interfere with llvm's ability to recognize the pattern but seems * a bit brittle. + * NOTE: llvm 9+ always uses (non arch specific) intrinsic. */ LLVMValueRef no_ov = lp_build_cmp(bld, PIPE_FUNC_GREATER, a, b); a = lp_build_select(bld, no_ov, a, b); -- 2.30.2