From e7c376adfdecd4c1333997c8be8bb066a87c67b4 Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Thu, 18 Aug 2016 15:54:47 -0700 Subject: [PATCH] i965/vec4: Ignore swizzle of VGRF for use by var_range_end(). var_range_end(v, n) loops over the n components of variable number v and finds the maximum value, giving the last use of any component of v. Therefore it expects v to correspond to the variable associated with the .x channel of the VGRF. var_from_reg() however returns the variable for the first channel of the VGRF, post-swizzle. So, if the last register had a swizzle with y, z, or w in the swizzle component, we would read out of bounds. For any other register, we would read liveness information from the next register. The fix is to convert the src_reg to a dst_reg in order to call the dst_reg version of var_from_reg() that doesn't consider the swizzle. Cc: mesa-stable@lists.freedesktop.org Reviewed-by: Francisco Jerez Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/brw_vec4.cpp | 2 +- src/mesa/drivers/dri/i965/brw_vec4_cse.cpp | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp index 2cf0e1759e4..a7398a797bb 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp @@ -1111,7 +1111,7 @@ vec4_visitor::opt_register_coalesce() /* Can't coalesce this GRF if someone else was going to * read it later. */ - if (var_range_end(var_from_reg(alloc, inst->src[0]), 4) > ip) + if (var_range_end(var_from_reg(alloc, dst_reg(inst->src[0])), 4) > ip) continue; /* We need to check interference with the final destination between this diff --git a/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp b/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp index 0c1f0c31b0d..10898a5917d 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp @@ -246,7 +246,7 @@ vec4_visitor::opt_cse_local(bblock_t *block) * more -- a sure sign they'll fail operands_match(). */ if (src->file == VGRF) { - if (var_range_end(var_from_reg(alloc, *src), 4) < ip) { + if (var_range_end(var_from_reg(alloc, dst_reg(*src)), 4) < ip) { entry->remove(); ralloc_free(entry); break; -- 2.30.2