i965/vec4: Emit MADs from (x + abs(y * z)).

Same as commit 3654b6d4 to the fs backend.

total instructions in shared programs: 5945788 -> 5945787 (-0.00%)
instructions in affected programs:     36 -> 35 (-2.78%)
helped:                                1

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 15 insertions, 3 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
index 2a988d0..c4c134f 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
@@ -1161,8 +1161,11 @@ vec4_visitor::try_emit_mad(ir_expression *ir)
    ir_rvalue *nonmul = ir->operands[1];
    ir_expression *mul = ir->operands[0]->as_expression();
 
-   bool mul_negate = false;
-   if (mul && mul->operation == ir_unop_neg) {
+   bool mul_negate = false, mul_abs = false;
+   if (mul && mul->operation == ir_unop_abs) {
+      mul = mul->operands[0]->as_expression();
+      mul_abs = true;
+   } else if (mul && mul->operation == ir_unop_neg) {
       mul = mul->operands[0]->as_expression();
       mul_negate = true;
    }
@@ -1171,7 +1174,10 @@ vec4_visitor::try_emit_mad(ir_expression *ir)
       nonmul = ir->operands[0];
       mul = ir->operands[1]->as_expression();
 
-      if (mul && mul->operation == ir_unop_neg) {
+      if (mul && mul->operation == ir_unop_abs) {
+         mul = mul->operands[0]->as_expression();
+         mul_abs = true;
+      } else if (mul && mul->operation == ir_unop_neg) {
          mul = mul->operands[0]->as_expression();
          mul_negate = true;
       }
@@ -1186,9 +1192,15 @@ vec4_visitor::try_emit_mad(ir_expression *ir)
    mul->operands[0]->accept(this);
    src_reg src1 = fix_3src_operand(this->result);
    src1.negate ^= mul_negate;
+   src1.abs = mul_abs;
+   if (mul_abs)
+      src1.negate = false;
 
    mul->operands[1]->accept(this);
    src_reg src2 = fix_3src_operand(this->result);
+   src2.abs = mul_abs;
+   if (mul_abs)
+      src2.negate = false;
 
    this->result = src_reg(this, ir->type);
    emit(BRW_OPCODE_MAD, dst_reg(this->result), src0, src1, src2);