From: Matt Turner <mattst88@gmail.com>
Date: Sat, 29 Aug 2015 00:10:00 +0000 (-0700)
Subject: i965/fs: Use greater-equal cmod to implement maximum.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=a4ba41638d41865ef34bf36a525efcf8102c01ee;p=mesa.git

i965/fs: Use greater-equal cmod to implement maximum.

The docs specifically call out SEL with .l and .ge as the
implementations of MIN and MAX respectively. Among other things,
SEL with these conditional mods are commutative.

See commit 3b7f683f.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
---

diff --git a/src/mesa/drivers/dri/i965/brw_fs_builder.h b/src/mesa/drivers/dri/i965/brw_fs_builder.h
index 34545eaa0fb..df10a9de293 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_builder.h
+++ b/src/mesa/drivers/dri/i965/brw_fs_builder.h
@@ -372,6 +372,8 @@ namespace brw {
       emit_minmax(const dst_reg &dst, const src_reg &src0,
                   const src_reg &src1, brw_conditional_mod mod) const
       {
+         assert(mod == BRW_CONDITIONAL_GE || mod == BRW_CONDITIONAL_L);
+
          if (shader->devinfo->gen >= 6) {
             set_condmod(mod, SEL(dst, fix_unsigned_negate(src0),
                                  fix_unsigned_negate(src1)));
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 50e0acd05f5..727e8d1b82a 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_surface_builder.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_surface_builder.cpp
@@ -686,7 +686,7 @@ namespace {
                if (is_signed)
                   bld.emit_minmax(offset(dst, bld, c), offset(dst, bld, c),
                                   fs_reg(-(int)scale(widths[c] - s) - 1),
-                                  BRW_CONDITIONAL_G);
+                                  BRW_CONDITIONAL_GE);
             }
          }
 
@@ -717,7 +717,7 @@ namespace {
                if (is_signed)
                   bld.emit_minmax(offset(dst, bld, c),
                                   offset(dst, bld, c), fs_reg(-1.0f),
-                                  BRW_CONDITIONAL_G);
+                                  BRW_CONDITIONAL_GE);
             }
          }
          return dst;
@@ -741,7 +741,7 @@ namespace {
                /* Clamp the normalized floating-point argument. */
                if (is_signed) {
                   bld.emit_minmax(offset(fdst, bld, c), offset(src, bld, c),
-                                  fs_reg(-1.0f), BRW_CONDITIONAL_G);
+                                  fs_reg(-1.0f), BRW_CONDITIONAL_GE);
 
                   bld.emit_minmax(offset(fdst, bld, c), offset(fdst, bld, c),
                                   fs_reg(1.0f), BRW_CONDITIONAL_L);
@@ -812,7 +812,7 @@ namespace {
                /* Clamp to the minimum value. */
                if (widths[c] < 16)
                   bld.emit_minmax(offset(fdst, bld, c), offset(fdst, bld, c),
-                                  fs_reg(0.0f), BRW_CONDITIONAL_G);
+                                  fs_reg(0.0f), BRW_CONDITIONAL_GE);
 
                /* Convert to 16-bit floating-point. */
                bld.F32TO16(offset(dst, bld, c), offset(fdst, bld, c));