From bfb95725aaa13a16011f16ad9ec9501b5a373ce6 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marek=20Ol=C5=A1=C3=A1k?= Date: Sat, 9 May 2020 23:00:44 -0400 Subject: [PATCH] ac/nir: select v_cvt_pkrtz for all conversions from f32 to f16 for radeonsi Reviewed-by: Samuel Pitoiset Part-of: --- src/amd/llvm/ac_nir_to_llvm.c | 43 +++++++++++++++++++++++++++++------ 1 file changed, 36 insertions(+), 7 deletions(-) diff --git a/src/amd/llvm/ac_nir_to_llvm.c b/src/amd/llvm/ac_nir_to_llvm.c index d47624a07e1..8a707c93666 100644 --- a/src/amd/llvm/ac_nir_to_llvm.c +++ b/src/amd/llvm/ac_nir_to_llvm.c @@ -943,18 +943,47 @@ static void visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr) result = LLVMBuildUIToFP(ctx->ac.builder, src[0], ac_to_float_type(&ctx->ac, def_type), ""); break; case nir_op_f2f16_rtz: + case nir_op_f2f16: + case nir_op_f2fmp: src[0] = ac_to_float(&ctx->ac, src[0]); - if (LLVMTypeOf(src[0]) == ctx->ac.f64) - src[0] = LLVMBuildFPTrunc(ctx->ac.builder, src[0], ctx->ac.f32, ""); - LLVMValueRef param[2] = { src[0], ctx->ac.f32_0 }; - result = ac_build_cvt_pkrtz_f16(&ctx->ac, param); - result = LLVMBuildExtractElement(ctx->ac.builder, result, ctx->ac.i32_0, ""); + + /* For OpenGL, we want fast packing with v_cvt_pkrtz_f16, but if we use it, + * all f32->f16 conversions have to round towards zero, because both scalar + * and vec2 down-conversions have to round equally. + */ + if (ctx->ac.float_mode == AC_FLOAT_MODE_DEFAULT_OPENGL || + instr->op == nir_op_f2f16_rtz) { + src[0] = ac_to_float(&ctx->ac, src[0]); + + if (LLVMTypeOf(src[0]) == ctx->ac.f64) + src[0] = LLVMBuildFPTrunc(ctx->ac.builder, src[0], ctx->ac.f32, ""); + + /* Fast path conversion. This only works if NIR is vectorized + * to vec2 16. + */ + if (LLVMTypeOf(src[0]) == ctx->ac.v2f32) { + LLVMValueRef args[] = { + ac_llvm_extract_elem(&ctx->ac, src[0], 0), + ac_llvm_extract_elem(&ctx->ac, src[0], 1), + }; + result = ac_build_cvt_pkrtz_f16(&ctx->ac, args); + break; + } + + assert(ac_get_llvm_num_components(src[0]) == 1); + LLVMValueRef param[2] = { src[0], ctx->ac.f32_0 }; + result = ac_build_cvt_pkrtz_f16(&ctx->ac, param); + result = LLVMBuildExtractElement(ctx->ac.builder, result, ctx->ac.i32_0, ""); + } else { + if (ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[0])) < ac_get_elem_bits(&ctx->ac, def_type)) + result = LLVMBuildFPExt(ctx->ac.builder, src[0], ac_to_float_type(&ctx->ac, def_type), ""); + else + result = LLVMBuildFPTrunc(ctx->ac.builder, src[0], ac_to_float_type(&ctx->ac, def_type), ""); + } break; case nir_op_f2f16_rtne: - case nir_op_f2f16: case nir_op_f2f32: case nir_op_f2f64: - case nir_op_f2fmp: src[0] = ac_to_float(&ctx->ac, src[0]); if (ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[0])) < ac_get_elem_bits(&ctx->ac, def_type)) result = LLVMBuildFPExt(ctx->ac.builder, src[0], ac_to_float_type(&ctx->ac, def_type), ""); -- 2.30.2