From a241ab43b5599f29c43e143bbcaaffef2af3e982 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Mon, 18 Jan 2016 17:30:59 -0800 Subject: [PATCH] i965/fs_surface_builder: Mask signed integers after conversion Reviewed-by: Francisco Jerez Reviewed-by: Jordan Justen --- src/mesa/drivers/dri/i965/brw_fs_surface_builder.cpp | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_fs_surface_builder.cpp b/src/mesa/drivers/dri/i965/brw_fs_surface_builder.cpp index 75734d2..96731ff 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_surface_builder.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_surface_builder.cpp @@ -717,6 +717,15 @@ namespace { bld.emit_minmax(offset(dst, bld, c), offset(dst, bld, c), brw_imm_d(-(int)scale(widths[c] - s) - 1), BRW_CONDITIONAL_GE); + + /* Mask off all but the bits we actually want. Otherwise, if + * we pass a negative number into the hardware when it's + * expecting something like UINT8, it will happily clamp it to + * +255 for us. + */ + if (is_signed && widths[c] < 32) + bld.AND(offset(dst, bld, c), offset(dst, bld, c), + brw_imm_d(scale(widths[c]))); } } @@ -787,6 +796,15 @@ namespace { /* Convert to integer. */ bld.RNDE(offset(fdst, bld, c), offset(fdst, bld, c)); bld.MOV(offset(dst, bld, c), offset(fdst, bld, c)); + + /* Mask off all but the bits we actually want. Otherwise, if + * we pass a negative number into the hardware when it's + * expecting something like UINT8, it will happily clamp it to + * +255 for us. + */ + if (is_signed && widths[c] < 32) + bld.AND(offset(dst, bld, c), offset(dst, bld, c), + brw_imm_d(scale(widths[c]))); } } -- 2.7.4