From 35a77a148f8b7ef03fe3b31d63719e0bfdf4b783 Mon Sep 17 00:00:00 2001 From: Francisco Jerez Date: Fri, 30 Jan 2015 17:50:35 +0200 Subject: i965: Don't compact instructions with unmapped bits. Some instruction bits don't have a mapping defined to any compacted instruction field. If they're ever set and we end up compacting the instruction they will be forced to zero. Avoid using compaction in such cases. v2: Align multiple lines of an expression to the same column. Change conditional compaction of 3-source instructions to an assertion. (Matt) v3: The 3-source instruction bit 105 is part of SourceIndex on CHV. Add assertion that reserved bit 7 is not set. (Matt) Document overlap with UIP and 64-bit immediate fields. v4: Make some more unmapped bit checks assertions. (Matt) Reviewed-by: Matt Turner --- src/mesa/drivers/dri/i965/brw_eu_compact.c | 53 ++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) (limited to 'src/mesa') diff --git a/src/mesa/drivers/dri/i965/brw_eu_compact.c b/src/mesa/drivers/dri/i965/brw_eu_compact.c index 8e33bcb0d83..26c41ea6ac5 100644 --- a/src/mesa/drivers/dri/i965/brw_eu_compact.c +++ b/src/mesa/drivers/dri/i965/brw_eu_compact.c @@ -842,12 +842,62 @@ set_3src_source_index(struct brw_context *brw, brw_compact_inst *dst, brw_inst * return false; } +static bool +has_unmapped_bits(struct brw_context *brw, brw_inst *src) +{ + /* Check for instruction bits that don't map to any of the fields of the + * compacted instruction. The instruction cannot be compacted if any of + * them are set. They overlap with: + * - NibCtrl (bit 47 on Gen7, bit 11 on Gen8) + * - Dst.AddrImm[9] (bit 47 on Gen8) + * - Src0.AddrImm[9] (bit 95 on Gen8) + * - Imm64[27:31] (bits 91-95 on Gen7, bit 95 on Gen8) + * - UIP[31] (bit 95 on Gen8) + */ + if (brw->gen >= 8) { + assert(!brw_inst_bits(src, 7, 7)); + return brw_inst_bits(src, 95, 95) || + brw_inst_bits(src, 47, 47) || + brw_inst_bits(src, 11, 11); + } else { + assert(!brw_inst_bits(src, 7, 7) && + !(brw->gen < 7 && brw_inst_bits(src, 90, 90))); + return brw_inst_bits(src, 95, 91) || + brw_inst_bits(src, 47, 47); + } +} + +static bool +has_3src_unmapped_bits(struct brw_context *brw, brw_inst *src) +{ + /* Check for three-source instruction bits that don't map to any of the + * fields of the compacted instruction. All of them seem to be reserved + * bits currently. + */ + if (brw->gen >= 9 || brw->is_cherryview) { + assert(!brw_inst_bits(src, 127, 127) && + !brw_inst_bits(src, 7, 7)); + } else { + assert(brw->gen >= 8); + assert(!brw_inst_bits(src, 127, 126) && + !brw_inst_bits(src, 105, 105) && + !brw_inst_bits(src, 84, 84) && + !brw_inst_bits(src, 36, 35) && + !brw_inst_bits(src, 7, 7)); + } + + return false; +} + static bool brw_try_compact_3src_instruction(struct brw_context *brw, brw_compact_inst *dst, brw_inst *src) { assert(brw->gen >= 8); + if (has_3src_unmapped_bits(brw, src)) + return false; + #define compact(field) \ brw_compact_inst_set_3src_##field(dst, brw_inst_3src_##field(brw, src)) @@ -937,6 +987,9 @@ brw_try_compact_instruction(struct brw_context *brw, brw_compact_inst *dst, return false; } + if (has_unmapped_bits(brw, src)) + return false; + memset(&temp, 0, sizeof(temp)); brw_compact_inst_set_opcode(&temp, brw_inst_opcode(brw, src)); -- cgit v1.2.3