From cc065e0ad739cc0219a95c0cb6684451fe2d9f9f 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 --- .../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 45694ec0894..f2faceeb579 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((1 << widths[c]) - 1)); } } @@ -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((1 << widths[c]) - 1)); } } -- 2.30.2