Mesa (10.2): nv50/ir: fix integer mul lowering for u32 x u32 -> high u32

[Ian Romanick]

Module: Mesa
Branch: 10.2
Commit: 9576e178045fd7727004950d6d76ec1a2cfbcaa1
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=9576e178045fd7727004950d6d76ec1a2cfbcaa1

Author: Ilia Mirkin <imirkin at alum.mit.edu>
Date:   Tue May 13 11:23:33 2014 -0400

nv50/ir: fix integer mul lowering for u32 x u32 -> high u32

UNION appears to expect that all of its sources are conditionally
defined. Otherwise it inserts an unpredicated mov instruction which
overwrites the desired result. This fixes tests that use UMUL_HI, and
much less directly, unsigned integer division by a constant, which uses
this functionality in a peephole pass.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: "10.1 10.2" <mesa-stable at lists.freedesktop.org>
Reviewed-by: Ben Skeggs <bskeggs at redhat.com>
(cherry picked from commit 5b8f1a0f7c5b1412577a913d374192a2329fa615)

---

 src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nv50.cpp |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nv50.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nv50.cpp
index 63db1d7..b17d57d 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nv50.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nv50.cpp
@@ -75,16 +75,17 @@ expandIntegerMUL(BuildUtil *bld, Instruction *mul)
    i[4] = bld->mkOp3(OP_MAD, fTy, t[3], a[0], b[0], t[2]);
 
    if (highResult) {
-      Value *r[3];
+      Value *r[4];
       Value *imm = bld->loadImm(NULL, 1 << (halfSize * 8));
       c[0] = bld->getSSA(1, FILE_FLAGS);
       c[1] = bld->getSSA(1, FILE_FLAGS);
-      for (int j = 0; j < 3; ++j)
+      for (int j = 0; j < 4; ++j)
          r[j] = bld->getSSA(fullSize);
 
       i[8] = bld->mkOp2(OP_SHR, fTy, r[0], t[1], bld->mkImm(halfSize * 8));
       i[6] = bld->mkOp2(OP_ADD, fTy, r[1], r[0], imm);
-      bld->mkOp2(OP_UNION, TYPE_U32, r[2], r[1], r[0]);
+      bld->mkMov(r[3], r[0])->setPredicate(CC_NC, c[0]);
+      bld->mkOp2(OP_UNION, TYPE_U32, r[2], r[1], r[3]);
       i[5] = bld->mkOp3(OP_MAD, fTy, mul->getDef(0), a[1], b[1], r[2]);
 
       // set carry defs / sources