Mesa (master): tgsi: make SSE ADD instruction SOA-safe

[Brian Paul]

Module: Mesa
Branch: master
Commit: 4b274f311c2c72e40e63c02e4a6f9f5ccc59f165
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=4b274f311c2c72e40e63c02e4a6f9f5ccc59f165

Author: Brian Paul <brianp at vmware.com>
Date:   Thu May  6 15:04:19 2010 -0600

tgsi: make SSE ADD instruction SOA-safe

To properly execute an instruction such as "ADD tmp, tmp.wzyx, foo;"
with SOA we (sometimes) need to put the results into temporaries before
writing the results to the destination register.

This patch fixes the ADD instruction but this needs to be done for
many more instructions.

Helps to fix piglit fp-long-alu test (fd.o bug 27989).

---

 src/gallium/auxiliary/tgsi/tgsi_sse2.c |   18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_sse2.c b/src/gallium/auxiliary/tgsi/tgsi_sse2.c
index 0820a41..01b4a96 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_sse2.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_sse2.c
@@ -1938,11 +1938,17 @@ emit_instruction(
       break;
 
    case TGSI_OPCODE_ADD:
+      /* do all fetches and adds, storing results in temp regs */
       FOR_EACH_DST0_ENABLED_CHANNEL( *inst, chan_index ) {
-         FETCH( func, *inst, 0, 0, chan_index );
-         FETCH( func, *inst, 1, 1, chan_index );
-         emit_add( func, 0, 1 );
-         STORE( func, *inst, 0, 0, chan_index );
+         int r = chan_index + 1;
+         FETCH( func, *inst, 0, 0, chan_index ); /* load xmm[0] */
+         FETCH( func, *inst, r, 1, chan_index ); /* load xmm[r] */
+         emit_add( func, r, 0 );   /* xmm[r] = xmm[r] + xmm[0] */
+      }
+      /* do all stores of the temp regs */
+      FOR_EACH_DST0_ENABLED_CHANNEL( *inst, chan_index ) {
+         int r = chan_index + 1;
+         STORE( func, *inst, r, 0, chan_index ); /* store xmm[r] */
       }
       break;
 
@@ -2825,8 +2831,10 @@ static void
 check_soa_dependencies(const struct tgsi_full_instruction *inst)
 {
    switch (inst->Instruction.Opcode) {
+   case TGSI_OPCODE_ADD:
+   case TGSI_OPCODE_MOV:
    case TGSI_OPCODE_XPD:
-      /* OK */
+      /* OK - these opcodes correctly handle SOA dependencies */
       break;
    default:
       if (tgsi_check_soa_dependencies(inst)) {