r600/fp64: fix integer->double conversion

Doing a straight uint/int->fp32->fp64 conversion causes
some precision issues, Roland suggested splitting the
integer into two portions and doing two separate
int->fp32->fp64 conversions then adding the results.

This passes the tests in CTS and piglit.

[airlied: fix cypress conversion opcodes]
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index b0931a3a8518bd9c9a80f96ef6094e163bee3ed4..e3b832b04f775f48055c86e2d565cf065299127b 100644 (file)
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -4490,44 +4490,109 @@ static int egcm_int_to_double(struct r600_shader_ctx *ctx)
 {
        struct tgsi_full_instruction *inst = &ctx->parse.FullToken.FullInstruction;
        struct r600_bytecode_alu alu;
-       int i, r;
-       int lasti = tgsi_last_instruction(inst->Dst[0].Register.WriteMask);
+       int i, c, r;
+       int write_mask = inst->Dst[0].Register.WriteMask;
+       int temp_reg = r600_get_temp(ctx);
 
        assert(inst->Instruction.Opcode == TGSI_OPCODE_I2D ||
                inst->Instruction.Opcode == TGSI_OPCODE_U2D);
 
-       for (i = 0; i <= (lasti+1)/2; i++) {
-               memset(&alu, 0, sizeof(struct r600_bytecode_alu));
-               alu.op = ctx->inst_info->op;
-
-               r600_bytecode_src(&alu.src[0], &ctx->src[0], i);
-               alu.dst.sel = ctx->temp_reg;
-               alu.dst.chan = i;
-               alu.dst.write = 1;
-               alu.last = 1;
+       for (c = 0; c < 2; c++) {
+               int dchan = c * 2;
+               if (write_mask & (0x3 << dchan)) {
+       /* split into 24-bit int and 8-bit int */
+                       memset(&alu, 0, sizeof(struct r600_bytecode_alu));
+                       alu.op = ALU_OP2_AND_INT;
+                       alu.dst.sel = temp_reg;
+                       alu.dst.chan = dchan;
+                       r600_bytecode_src(&alu.src[0], &ctx->src[0], c);
+                       alu.src[1].sel = V_SQ_ALU_SRC_LITERAL;
+                       alu.src[1].value = 0xffffff00;
+                       alu.dst.write = 1;
+                       r = r600_bytecode_add_alu(ctx->bc, &alu);
+                       if (r)
+                               return r;
 
-               r = r600_bytecode_add_alu(ctx->bc, &alu);
-               if (r)
-                       return r;
+                       memset(&alu, 0, sizeof(struct r600_bytecode_alu));
+                       alu.op = ALU_OP2_AND_INT;
+                       alu.dst.sel = temp_reg;
+                       alu.dst.chan = dchan + 1;
+                       r600_bytecode_src(&alu.src[0], &ctx->src[0], c);
+                       alu.src[1].sel = V_SQ_ALU_SRC_LITERAL;
+                       alu.src[1].value = 0xff;
+                       alu.dst.write = 1;
+                       alu.last = 1;
+                       r = r600_bytecode_add_alu(ctx->bc, &alu);
+                       if (r)
+                               return r;
+               }
        }
 
-       for (i = 0; i <= lasti; i++) {
-               memset(&alu, 0, sizeof(struct r600_bytecode_alu));
-               alu.op = ALU_OP1_FLT32_TO_FLT64;
+       for (c = 0; c < 2; c++) {
+               int dchan = c * 2;
+               if (write_mask & (0x3 << dchan)) {
+                       for (i = dchan; i <= dchan + 1; i++) {
+                               memset(&alu, 0, sizeof(struct r600_bytecode_alu));
+                               alu.op = i == dchan ? ctx->inst_info->op : ALU_OP1_UINT_TO_FLT;
 
-               alu.src[0].chan = i/2;
-               if (i%2 == 0)
-                       alu.src[0].sel = ctx->temp_reg;
-               else {
-                       alu.src[0].sel = V_SQ_ALU_SRC_LITERAL;
-                       alu.src[0].value = 0x0;
+                               alu.src[0].sel = temp_reg;
+                               alu.src[0].chan = i;
+                               alu.dst.sel = temp_reg;
+                               alu.dst.chan = i;
+                               alu.dst.write = 1;
+                               if (ctx.bc->chip_class == CAYMAN)
+                                       alu.last = i == dchan + 1;
+                               else
+                                       alu.last = 1; /* trans only ops on evergreen */
+                               
+                               r = r600_bytecode_add_alu(ctx->bc, &alu);
+                               if (r)
+                                       return r;
+                       }
                }
-               tgsi_dst(ctx, &inst->Dst[0], i, &alu.dst);
-               alu.last = i == lasti;
+       }
 
-               r = r600_bytecode_add_alu(ctx->bc, &alu);
-               if (r)
-                       return r;
+       for (c = 0; c < 2; c++) {
+               int dchan = c * 2;
+               if (write_mask & (0x3 << dchan)) {
+                       for (i = 0; i < 4; i++) {
+                               memset(&alu, 0, sizeof(struct r600_bytecode_alu));
+                               alu.op = ALU_OP1_FLT32_TO_FLT64;
+
+                               alu.src[0].chan = dchan + (i / 2);
+                               if (i == 0 || i == 2)
+                                       alu.src[0].sel = temp_reg;
+                               else {
+                                       alu.src[0].sel = V_SQ_ALU_SRC_LITERAL;
+                                       alu.src[0].value = 0x0;
+                               }
+                               alu.dst.sel = ctx->temp_reg;
+                               alu.dst.chan = i;
+                               alu.last = i == 3;
+                               alu.dst.write = 1;
+
+                               r = r600_bytecode_add_alu(ctx->bc, &alu);
+                               if (r)
+                                       return r;
+                       }
+
+                       for (i = 0; i <= 1; i++) {
+                               memset(&alu, 0, sizeof(struct r600_bytecode_alu));
+                               alu.op = ALU_OP2_ADD_64;
+
+                               alu.src[0].chan = fp64_switch(i);
+                               alu.src[0].sel = ctx->temp_reg;
+
+                               alu.src[1].chan = fp64_switch(i + 2);
+                               alu.src[1].sel = ctx->temp_reg;
+                               tgsi_dst(ctx, &inst->Dst[0], dchan + i, &alu.dst);
+                               alu.last = i == 1;
+
+                               r = r600_bytecode_add_alu(ctx->bc, &alu);
+                               if (r)
+                                       return r;
+                       }
+               }
        }
 
        return 0;