r300/compiler: saturate Z before the shadow comparison

This fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=31159

NOTE: This is a candidate for the 7.9 and 7.10 branches.

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_program_tex.c b/src/mesa/drivers/dri/r300/compiler/radeon_program_tex.c
index f9d9f34b6ad9f7e25629450df2ee144f88f0b779..a58ef06b86f1477eaf110a2ea225ee5cf8ed824f 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/radeon_program_tex.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_program_tex.c
@@ -137,6 +137,13 @@ int radeonTransformTEX(
                 (compiler->state.unit[inst->U.I.TexSrcUnit].compare_mode_enabled))) {
                rc_compare_func comparefunc = compiler->state.unit[inst->U.I.TexSrcUnit].texture_compare_func;
 
+               /* Fake EQUAL/NOTEQUAL, they are equal to NEVER/ALWAYS due to precision issues anyway. */
+               if (comparefunc == RC_COMPARE_FUNC_EQUAL) {
+                       comparefunc = RC_COMPARE_FUNC_NEVER;
+               } else if (comparefunc == RC_COMPARE_FUNC_NOTEQUAL) {
+                       comparefunc = RC_COMPARE_FUNC_ALWAYS;
+               }
+
                if (comparefunc == RC_COMPARE_FUNC_NEVER || comparefunc == RC_COMPARE_FUNC_ALWAYS) {
                        inst->U.I.Opcode = RC_OPCODE_MOV;
 
@@ -149,14 +156,11 @@ int radeonTransformTEX(
 
                        return 1;
                } else {
-                       rc_compare_func comparefunc = compiler->state.unit[inst->U.I.TexSrcUnit].texture_compare_func;
                        struct rc_instruction * inst_rcp = NULL;
-                       struct rc_instruction * inst_mad;
-                       struct rc_instruction * inst_cmp;
+                       struct rc_instruction *inst_mul, *inst_cmp, *inst_add;
                        unsigned tmp_texsample;
                        unsigned tmp_sum;
-                       unsigned tmp_recip_w = 0;
-                       int pass, fail, tex;
+                       int pass, fail;
 
                        /* Save the output register. */
                        struct rc_dst_register output_reg = inst->U.I.DstReg;
@@ -167,49 +171,49 @@ int radeonTransformTEX(
                        inst->U.I.DstReg.Index = tmp_texsample;
                        inst->U.I.DstReg.WriteMask = RC_MASK_XYZW;
 
-                       if (inst->U.I.Opcode == RC_OPCODE_TXP) {
-                               tmp_recip_w = rc_find_free_temporary(c);
+                       tmp_sum = rc_find_free_temporary(c);
 
+                       if (inst->U.I.Opcode == RC_OPCODE_TXP) {
                                /* Compute 1/W. */
                                inst_rcp = rc_insert_new_instruction(c, inst);
                                inst_rcp->U.I.Opcode = RC_OPCODE_RCP;
                                inst_rcp->U.I.DstReg.File = RC_FILE_TEMPORARY;
-                               inst_rcp->U.I.DstReg.Index = tmp_recip_w;
+                               inst_rcp->U.I.DstReg.Index = tmp_sum;
                                inst_rcp->U.I.DstReg.WriteMask = RC_MASK_W;
                                inst_rcp->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
                                inst_rcp->U.I.SrcReg[0].Swizzle =
                                        RC_MAKE_SWIZZLE_SMEAR(GET_SWZ(inst->U.I.SrcReg[0].Swizzle, 3));
                        }
 
-                       /* Perspective-divide Z by W (if it's TXP) and add the texture sample (see below). */
-                       tmp_sum = rc_find_free_temporary(c);
-                       inst_mad = rc_insert_new_instruction(c, inst_rcp ? inst_rcp : inst);
-                       inst_mad->U.I.DstReg.File = RC_FILE_TEMPORARY;
-                       inst_mad->U.I.DstReg.Index = tmp_sum;
-                       inst_mad->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
-                       inst_mad->U.I.SrcReg[0].Swizzle =
+                       /* Divide Z by W (if it's TXP) and saturate. */
+                       inst_mul = rc_insert_new_instruction(c, inst_rcp ? inst_rcp : inst);
+                       inst_mul->U.I.Opcode = inst->U.I.Opcode == RC_OPCODE_TXP ? RC_OPCODE_MUL : RC_OPCODE_MOV;
+                       inst_mul->U.I.DstReg.File = RC_FILE_TEMPORARY;
+                       inst_mul->U.I.DstReg.Index = tmp_sum;
+                       inst_mul->U.I.DstReg.WriteMask = RC_MASK_W;
+                       inst_mul->U.I.SaturateMode = RC_SATURATE_ZERO_ONE;
+                       inst_mul->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
+                       inst_mul->U.I.SrcReg[0].Swizzle =
                                RC_MAKE_SWIZZLE_SMEAR(GET_SWZ(inst->U.I.SrcReg[0].Swizzle, 2));
                        if (inst->U.I.Opcode == RC_OPCODE_TXP) {
-                               inst_mad->U.I.Opcode = RC_OPCODE_MAD;
-                               inst_mad->U.I.SrcReg[1].File = RC_FILE_TEMPORARY;
-                               inst_mad->U.I.SrcReg[1].Index = tmp_recip_w;
-                               inst_mad->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_WWWW;
-                               tex = 2;
-                       } else {
-                               inst_mad->U.I.Opcode = RC_OPCODE_ADD;
-                               tex = 1;
-                       }
-                       inst_mad->U.I.SrcReg[tex].File = RC_FILE_TEMPORARY;
-                       inst_mad->U.I.SrcReg[tex].Index = tmp_texsample;
-                       inst_mad->U.I.SrcReg[tex].Swizzle = compiler->state.unit[inst->U.I.TexSrcUnit].depth_texture_swizzle;
-
-                       /* Fake EQUAL/NOTEQUAL, it seems to pass some tests suprisingly. */
-                       if (comparefunc == RC_COMPARE_FUNC_EQUAL) {
-                               comparefunc = RC_COMPARE_FUNC_GEQUAL;
-                       } else if (comparefunc == RC_COMPARE_FUNC_NOTEQUAL) {
-                               comparefunc = RC_COMPARE_FUNC_LESS;
+                               inst_mul->U.I.SrcReg[1].File = RC_FILE_TEMPORARY;
+                               inst_mul->U.I.SrcReg[1].Index = tmp_sum;
+                               inst_mul->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_WWWW;
                        }
 
+                       /* Add the depth texture value. */
+                       inst_add = rc_insert_new_instruction(c, inst_mul);
+                       inst_add->U.I.Opcode = RC_OPCODE_ADD;
+                       inst_add->U.I.DstReg.File = RC_FILE_TEMPORARY;
+                       inst_add->U.I.DstReg.Index = tmp_sum;
+                       inst_add->U.I.DstReg.WriteMask = RC_MASK_W;
+                       inst_add->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
+                       inst_add->U.I.SrcReg[0].Index = tmp_sum;
+                       inst_add->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_WWWW;
+                       inst_add->U.I.SrcReg[1].File = RC_FILE_TEMPORARY;
+                       inst_add->U.I.SrcReg[1].Index = tmp_texsample;
+                       inst_add->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_WWWW;
+
                        /* Recall that SrcReg[0] is r, SrcReg[tex] is tex and:
                         *   LESS:    r  < tex  <=>      -tex+r < 0
                         *   GEQUAL:  r >= tex  <=> not (-tex+r < 0)
@@ -218,9 +222,9 @@ int radeonTransformTEX(
                         *
                         * This negates either r or tex: */
                        if (comparefunc == RC_COMPARE_FUNC_LESS || comparefunc == RC_COMPARE_FUNC_GEQUAL)
-                               inst_mad->U.I.SrcReg[tex].Negate = inst_mad->U.I.SrcReg[tex].Negate ^ RC_MASK_XYZW;
+                               inst_add->U.I.SrcReg[1].Negate = inst_add->U.I.SrcReg[1].Negate ^ RC_MASK_XYZW;
                        else
-                               inst_mad->U.I.SrcReg[0].Negate = inst_mad->U.I.SrcReg[0].Negate ^ RC_MASK_XYZW;
+                               inst_add->U.I.SrcReg[0].Negate = inst_add->U.I.SrcReg[0].Negate ^ RC_MASK_XYZW;
 
                        /* This negates the whole expresion: */
                        if (comparefunc == RC_COMPARE_FUNC_LESS || comparefunc == RC_COMPARE_FUNC_GREATER) {
@@ -231,16 +235,19 @@ int radeonTransformTEX(
                                fail = 1;
                        }
 
-                       inst_cmp = rc_insert_new_instruction(c, inst_mad);
+                       inst_cmp = rc_insert_new_instruction(c, inst_add);
                        inst_cmp->U.I.Opcode = RC_OPCODE_CMP;
                        inst_cmp->U.I.DstReg = output_reg;
                        inst_cmp->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
                        inst_cmp->U.I.SrcReg[0].Index = tmp_sum;
+                       inst_cmp->U.I.SrcReg[0].Swizzle =
+                               combine_swizzles(RC_SWIZZLE_WWWW,
+                                                compiler->state.unit[inst->U.I.TexSrcUnit].depth_texture_swizzle);
                        inst_cmp->U.I.SrcReg[pass].File = RC_FILE_NONE;
                        inst_cmp->U.I.SrcReg[pass].Swizzle = RC_SWIZZLE_1111;
                        inst_cmp->U.I.SrcReg[fail] = shadow_ambient(compiler, inst->U.I.TexSrcUnit);
 
-                       assert(tmp_texsample != tmp_sum && tmp_sum != tmp_recip_w);
+                       assert(tmp_texsample != tmp_sum);
                }
        }