[hsa-branch 6/9] Expand FMA_EXPR to HSAIL

[Martin Jambor]

Hi,

the following patch adds expansion of fused multiply and add to HSAIL.
The scalar variant is straightforwardly converted to an HSAIL equivalent
while any vector instance is expanded into separate multiplication and
additions.

Committed to the branch, queued for merge to trunk soon.
Thanks,

Martin

2016-10-03  Martin Jambor  <mjam...@suse.cz>

        * hsa-gen.c (gen_hsa_insns_for_operation_assignment): Handle
        FMA_EXPR and ternary operators in general.  Remove obsolete
        fallthrough comments.
---
 gcc/hsa-gen.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/gcc/hsa-gen.c b/gcc/hsa-gen.c
index ac83e9e..ad40087 100644
--- a/gcc/hsa-gen.c
+++ b/gcc/hsa-gen.c
@@ -3076,6 +3076,23 @@ gen_hsa_insns_for_operation_assignment (gimple *assign, 
hsa_bb *hbb)
     case NEGATE_EXPR:
       opcode = BRIG_OPCODE_NEG;
       break;
+    case FMA_EXPR:
+      /* There is a native HSA instruction for scalar FMAs but not for vector
+        ones.  */
+      if (TREE_CODE (TREE_TYPE (lhs)) == VECTOR_TYPE)
+       {
+         hsa_op_reg *dest
+           = hsa_cfun->reg_for_gimple_ssa (gimple_assign_lhs (assign));
+         hsa_op_with_type *op1 = hsa_reg_or_immed_for_gimple_op (rhs1, hbb);
+         hsa_op_with_type *op2 = hsa_reg_or_immed_for_gimple_op (rhs2, hbb);
+         hsa_op_with_type *op3 = hsa_reg_or_immed_for_gimple_op (rhs3, hbb);
+         hsa_op_reg *tmp = new hsa_op_reg (dest->m_type);
+         gen_hsa_binary_operation (BRIG_OPCODE_MUL, tmp, op1, op2, hbb);
+         gen_hsa_binary_operation (BRIG_OPCODE_ADD, dest, tmp, op3, hbb);
+         return;
+       }
+      opcode = BRIG_OPCODE_MAD;
+      break;
     case MIN_EXPR:
       opcode = BRIG_OPCODE_MIN;
       break;
@@ -3275,14 +3292,18 @@ gen_hsa_insns_for_operation_assignment (gimple *assign, 
hsa_bb *hbb)
   switch (rhs_class)
     {
     case GIMPLE_TERNARY_RHS:
-      gcc_unreachable ();
+      {
+       hsa_op_with_type *op3 = hsa_reg_or_immed_for_gimple_op (rhs3, hbb);
+       hsa_insn_basic *insn = new hsa_insn_basic (4, opcode, dest->m_type, 
dest,
+                                                  op1, op2, op3);
+       hbb->append_insn (insn);
+      }
       return;
 
-      /* Fall through */
     case GIMPLE_BINARY_RHS:
       gen_hsa_binary_operation (opcode, dest, op1, op2, hbb);
       break;
-      /* Fall through */
+
     case GIMPLE_UNARY_RHS:
       gen_hsa_unary_operation (opcode, dest, op1, hbb);
       break;
-- 
2.10.0