Created attachment 100179 [details] failing tgsi shader The attached shader fails in the RA step, when inserting spill code: nv50_ir::SpillCodeInserter::run (this=0x7ffffffec0c0, lst=std::list) at codegen/nv50_ir_ra.cpp:1561 1561 while (!dval->uses.empty()) { Easily reproduced with nouveau_compiler -a c0. Apparently this shader is generated as part of the d3d9 st, with skyrimlauncher, when it's trying to detect the graphics card. dval is null, which means that something out there isn't an lvalue. Or, in this case, apparently a null value?? (gdb) p *defi $4 = {_vptr.Instruction = 0x86e570, next = 0x0, prev = 0x0, id = -1, serial = 27, op = nv50_ir::OP_SPLIT, dType = nv50_ir::TYPE_B128, sType = nv50_ir::TYPE_B128, cc = nv50_ir::CC_TR, rnd = nv50_ir::ROUND_N, cache = nv50_ir::CACHE_CA, subOp = 0, encSize = 0, saturate = 0, join = 0, fixed = 0, terminator = 0, ftz = 0, dnz = 0, ipa = 0, lanes = 15, perPatch = 0, exit = 0, mask = 0, postFactor = 0 '\000', predSrc = -1 '\377', flagsDef = -1 '\377', flagsSrc = -1 '\377', sched = 0, bb = 0x0, defs = std::deque with 4 elements = {{value = 0x0, origin = 0x0, insn = 0x200}, {value = 0x85ce30, origin = 0x7ffff71a0698 <main_arena+88>, insn = 0x9e5e40}, {value = 0x0, origin = 0x0, insn = 0x9e5e40}, {value = 0x0, origin = 0x0, insn = 0x9e5e40}}, srcs = std::deque with 1 elements = {{mod = {bits = 0 '\000'}, indirect = "\377\377", swizzle = 0 '\000', usedAsPtr = false, value = 0x0, insn = 0x200}}} Note that the second def isn't null but the others are? Perhaps this happens as part of dead code elimination? Need to investigate more.
The below patch helps avoid the crash, but it still still generate incorrect code. I think there are a few issues here, and I'll have to think a little harder about how to properly resolve them. diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp index 5ab6570..89c83cb 100644 --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp @@ -1576,7 +1576,8 @@ SpillCodeInserter::run(const std::list<ValuePair>& lst) assert(defi); if (defi->isPseudo()) { - d = lval->defs.erase(d); + while (d != lval->defs.end() && (*d)->getInsn() == defi) + d = lval->defs.erase(d); --d; if (slot->reg.file == FILE_MEMORY_LOCAL) delete_Instruction(func->getProgram(), defi);
I've spent a bunch of time looking at this issue. So *one* of the problems is that we delete the instruction too early. But I think there's more going on. Still debugging. The issue happens if we want to spill a value that is split.
http://patchwork.freedesktop.org/patch/34098/ Please see if this helps.
I've pushed out the fix, makes at least the attached shader compile. It also fixed UE4 demos which appear to render fine. Should get backported to 10.3 and probably 10.2 as well. commit 0147c10c5f00b43696ba660aab604d674a75e83c Author: Ilia Mirkin <imirkin@alum.mit.edu> Date: Wed Sep 24 21:45:07 2014 -0400 nv50/ir: avoid deleting pseudo instructions too early
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