From ba6cd796dd60635ca12f036ba9de5b907d8e82f5 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Fri, 7 Jun 2013 13:31:58 +0100 Subject: [PATCH] llvmpipe: Use saturating add/sub for UNORM formats lp_build_add and lp_build_sub have fallback code for cases that cannot be handled by known intrinsics. For UNORM formats, this code was using modulo rather than saturating arithmetic. This fixes some rendering issues for a gnome session on System z. It also fixes various piglit tests on z, such as spec/ARB_color_buffer_float/GL_RGBA8-render. The patch deliberately doesn't tackle the more complicated SNORM case. Tested against piglit on x86_64 and System z with no regressions. Reviewed-by: Adam Jackson Signed-off-by: Richard Sandiford --- src/gallium/auxiliary/gallivm/lp_bld_arit.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c index 3291ec40af5..08aec799a33 100644 --- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c +++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c @@ -386,6 +386,10 @@ lp_build_add(struct lp_build_context *bld, return lp_build_intrinsic_binary(builder, intrinsic, lp_build_vec_type(bld->gallivm, bld->type), a, b); } + /* TODO: handle signed case */ + if(type.norm && !type.floating && !type.fixed && !type.sign) + a = lp_build_min_simple(bld, a, lp_build_comp(bld, b)); + if(LLVMIsConstant(a) && LLVMIsConstant(b)) if (type.floating) res = LLVMConstFAdd(a, b); @@ -663,6 +667,10 @@ lp_build_sub(struct lp_build_context *bld, return lp_build_intrinsic_binary(builder, intrinsic, lp_build_vec_type(bld->gallivm, bld->type), a, b); } + /* TODO: handle signed case */ + if(type.norm && !type.floating && !type.fixed && !type.sign) + a = lp_build_max_simple(bld, a, b); + if(LLVMIsConstant(a) && LLVMIsConstant(b)) if (type.floating) res = LLVMConstFSub(a, b); -- 2.30.2