From d64c6d2ffc086bde7a025269b80c0980f7d908f1 Mon Sep 17 00:00:00 2001 From: Tom Stellard Date: Sat, 1 Oct 2011 15:22:24 -0700 Subject: [PATCH] r300/compiler: Fix error in OMOD optimization Classic compiler mistake. In the example below, the OMOD optimization was combining instructions 4 and 10, but since there was an instruction (#8) in between them that wrote to the same registers as instruction 10, instruction 11 was reading the wrong value. Example of the mistake: Before OMOD: 4: MAD temp[0].y, temp[3]._y__, const[0]._x__, const[0]._y__; ... 8: ADD temp[2].x, temp[1].x___, -temp[4].x___; ... 10: MUL temp[2].x, const[1].y___, temp[0].y___; 11: FRC temp[5].x, temp[2].x___; After OMOD: 4: MAD temp[2].x / 8, temp[3]._y__, const[0]._x__, const[0]._y__; ... 8: ADD temp[2].x, temp[1].x___, -temp[4].x___; ... 11: FRC temp[5].x, temp[2].x___; https://bugs.freedesktop.org/show_bug.cgi?id=41367 --- .../drivers/r300/compiler/radeon_optimize.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/gallium/drivers/r300/compiler/radeon_optimize.c b/src/gallium/drivers/r300/compiler/radeon_optimize.c index b7a0e20797c..2d799a6547a 100644 --- a/src/gallium/drivers/r300/compiler/radeon_optimize.c +++ b/src/gallium/drivers/r300/compiler/radeon_optimize.c @@ -681,6 +681,20 @@ static void omod_filter_reader_cb( } } +static void omod_filter_writer_cb( + void * userdata, + struct rc_instruction * inst, + rc_register_file file, + unsigned int index, + unsigned int mask) +{ + struct peephole_mul_cb_data * d = userdata; + if (file == d->Writer->File && index == d->Writer->Index && + (mask & d->Writer->WriteMask)) { + d->Clobbered = 1; + } +} + static int peephole_mul_omod( struct radeon_compiler * c, struct rc_instruction * inst_mul, @@ -788,6 +802,8 @@ static int peephole_mul_omod( inst = inst->Prev) { rc_for_all_reads_mask(inst, omod_filter_reader_cb, &cb_data); + rc_for_all_writes_mask(inst, omod_filter_writer_cb, + &cb_data); if (cb_data.Clobbered) { break; } -- 2.30.2