[Mesa-dev] [PATCH 1/2] nir: add an isinf opcode, and an option to use it.

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

In order to get isinf(NaN) correct, at least radv can't
use an unordered equals which feq has to be for us, this
passes isinf to the backend and let's it sort it out as it
pleases.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 src/compiler/nir/nir.h          | 1 +
 src/compiler/nir/nir_opcodes.py | 2 +-
 src/compiler/spirv/vtn_alu.c    | 7 +++++--
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 57b8be3..bcdca4b 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -1777,6 +1777,7 @@ typedef struct nir_shader_compiler_options {
    bool lower_bitfield_insert;
    bool lower_uadd_carry;
    bool lower_usub_borrow;
+   bool use_isinf;
    /** lowers fneg and ineg to fsub and isub. */
    bool lower_negate;
    /** lowers fsub and isub to fadd+fneg and iadd+ineg. */
diff --git a/src/compiler/nir/nir_opcodes.py b/src/compiler/nir/nir_opcodes.py
index 52868d5..7387208 100644
--- a/src/compiler/nir/nir_opcodes.py
+++ b/src/compiler/nir/nir_opcodes.py
@@ -203,7 +203,7 @@ unop("fquantize2f16", tfloat, "(fabs(src0) < ldexpf(1.0, -14)) ? copysignf(0.0f,
 unop("fsin", tfloat, "bit_size == 64 ? sin(src0) : sinf(src0)")
 unop("fcos", tfloat, "bit_size == 64 ? cos(src0) : cosf(src0)")
 
-
+unop_convert("isinf", tbool, tfloat, "isinf(src0)")
 # Partial derivatives.
 
 
diff --git a/src/compiler/spirv/vtn_alu.c b/src/compiler/spirv/vtn_alu.c
index 0738fe0..79f51e7 100644
--- a/src/compiler/spirv/vtn_alu.c
+++ b/src/compiler/spirv/vtn_alu.c
@@ -447,8 +447,11 @@ vtn_handle_alu(struct vtn_builder *b, SpvOp opcode,
       break;
 
    case SpvOpIsInf:
-      val->ssa->def = nir_feq(&b->nb, nir_fabs(&b->nb, src[0]),
-                                      nir_imm_float(&b->nb, INFINITY));
+      if (b->shader->options->use_isinf)
+         val->ssa->def = nir_isinf(&b->nb, src[0]);
+      else
+         val->ssa->def = nir_feq(&b->nb, nir_fabs(&b->nb, src[0]),
+                                 nir_imm_float(&b->nb, INFINITY));
       break;
 
    case SpvOpFUnordEqual:
-- 
2.9.3