From 50e913b9c5d311334281da89b4e9969d48fd62b6 Mon Sep 17 00:00:00 2001 From: Ilia Mirkin Date: Fri, 10 Nov 2017 22:10:46 -0500 Subject: [PATCH] nv50/ir: add optimization for modulo by a non-power-of-2 value We can still use the optimized division methods which make use of multiplication with overflow. Signed-off-by: Ilia Mirkin Reviewed-by: Tobias Klausmann --- .../drivers/nouveau/codegen/nv50_ir_peephole.cpp | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp index 2448c737e73..cfd623ea877 100644 --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp @@ -1192,6 +1192,21 @@ ConstantFolding::opnd(Instruction *i, ImmediateValue &imm0, int s) delete_Instruction(prog, i); } + } else if (s == 1) { + // In this case, we still want the optimized lowering that we get + // from having division by an immediate. + // + // a % b == a - (a/b) * b + bld.setPosition(i, false); + Value *div = bld.mkOp2v(OP_DIV, i->sType, bld.getSSA(), + i->getSrc(0), i->getSrc(1)); + newi = bld.mkOp2(OP_ADD, i->sType, i->getDef(0), i->getSrc(0), + bld.mkOp2v(OP_MUL, i->sType, bld.getSSA(), div, i->getSrc(1))); + // TODO: Check that target supports this. In this case, we know that + // all backends do. + newi->src(1).mod = Modifier(NV50_IR_MOD_NEG); + + delete_Instruction(prog, i); } break; -- 2.30.2