From 571cbd05ebfb8bef22277c5758afc82f5dd6a3f2 Mon Sep 17 00:00:00 2001 From: "Juan A. Suarez Romero" Date: Fri, 20 Jan 2017 08:50:50 +0100 Subject: i965/fs: fix dst stride in IVB/BYT type conversions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When converting a DF to 32-bit conversions, we set dst stride to 2, to fulfill alignment restrictions because the upper Dword of every Qword will be written with undefined value. But in IVB/BYT, this is not necessary, as each DF conversion already writes 2, the first one the real value, and the second one a 0. That is, IVB/BYT already set stride = 2 implicitly, so we must set it to 1 explicitly to avoid ending up with stride = 4. v2: - Fix typo (Matt) v3: - Fix stride in the destination's brw_reg, don't modity IR (Curro) v4: - Remove 'is_dst' argument of brw_reg_from_fs_reg() (Curro) - Fix comment (Curro). - Relax hstride assert (Curro) Signed-off-by: Juan A. Suarez Romero Signed-off-by: Samuel Iglesias Gonsálvez [ Francisco Jerez: Minor spelling fixes. ] Reviewed-by: Francisco Jerez --- src/intel/compiler/brw_fs_generator.cpp | 68 ++++++++++++++++++++------------- 1 file changed, 41 insertions(+), 27 deletions(-) diff --git a/src/intel/compiler/brw_fs_generator.cpp b/src/intel/compiler/brw_fs_generator.cpp index bc15fd11d9..16083a70d7 100644 --- a/src/intel/compiler/brw_fs_generator.cpp +++ b/src/intel/compiler/brw_fs_generator.cpp @@ -93,33 +93,47 @@ brw_reg_from_fs_reg(const struct gen_device_info *devinfo, fs_inst *inst, const unsigned width = MIN2(reg_width, phys_width); brw_reg = brw_vecn_reg(width, brw_file_from_reg(reg), reg->nr, 0); brw_reg = stride(brw_reg, width * reg->stride, width, reg->stride); - /* From the IvyBridge PRM (EU Changes by Processor Generation, page 13): - * "Each DF (Double Float) operand uses an element size of 4 rather - * than 8 and all regioning parameters are twice what the values - * would be based on the true element size: ExecSize, Width, - * HorzStride, and VertStride. Each DF operand uses a pair of - * channels and all masking and swizzing should be adjusted - * appropriately." - * - * From the IvyBridge PRM (Special Requirements for Handling Double - * Precision Data Types, page 71): - * "In Align1 mode, all regioning parameters like stride, execution - * size, and width must use the syntax of a pair of packed - * floats. The offsets for these data types must be 64-bit - * aligned. The execution size and regioning parameters are in terms - * of floats." - * - * Summarized: when handling DF-typed arguments, ExecSize, - * VertStride, and Width must be doubled. - * - * It applies to BayTrail too. - */ - if (devinfo->gen == 7 && !devinfo->is_haswell && - type_sz(reg->type) == 8) { - brw_reg.width++; - if (brw_reg.vstride > 0) - brw_reg.vstride++; - assert(brw_reg.hstride == BRW_HORIZONTAL_STRIDE_1); + + if (devinfo->gen == 7 && !devinfo->is_haswell) { + /* From the IvyBridge PRM (EU Changes by Processor Generation, page 13): + * "Each DF (Double Float) operand uses an element size of 4 rather + * than 8 and all regioning parameters are twice what the values + * would be based on the true element size: ExecSize, Width, + * HorzStride, and VertStride. Each DF operand uses a pair of + * channels and all masking and swizzing should be adjusted + * appropriately." + * + * From the IvyBridge PRM (Special Requirements for Handling Double + * Precision Data Types, page 71): + * "In Align1 mode, all regioning parameters like stride, execution + * size, and width must use the syntax of a pair of packed + * floats. The offsets for these data types must be 64-bit + * aligned. The execution size and regioning parameters are in terms + * of floats." + * + * Summarized: when handling DF-typed arguments, ExecSize, + * VertStride, and Width must be doubled. + * + * It applies to BayTrail too. + */ + if (type_sz(reg->type) == 8) { + brw_reg.width++; + if (brw_reg.vstride > 0) + brw_reg.vstride++; + assert(brw_reg.hstride == BRW_HORIZONTAL_STRIDE_1); + } + + /* When converting from DF->F, we set the destination stride to 2 + * because each d2f conversion implicitly writes 2 floats, being + * the first one the converted value. IVB/BYT actually writes two + * F components per SIMD channel, and every other component is + * filled with garbage. + */ + if (reg == &inst->dst && get_exec_type_size(inst) == 8 && + type_sz(inst->dst.type) < 8) { + assert(brw_reg.hstride > BRW_HORIZONTAL_STRIDE_1); + brw_reg.hstride--; + } } } -- cgit v1.2.3