Mesa (master): aco/isel: Fix i64/u64->float32 conversion for large inputs

[GitLab Mirror]

Module: Mesa
Branch: master
Commit: 3a2b0557265f1aea58535b1df933f1124cce6544
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3a2b0557265f1aea58535b1df933f1124cce6544

Author: Tony Wasserka <tony.wasserka at gmx.de>
Date:   Mon Mar 15 12:26:51 2021 +0100

aco/isel: Fix i64/u64->float32 conversion for large inputs

Previously, inputs such as 0x100000000 would have their upper 32-bits
ignored despite being representable by 32-bit floats.

Reviewed-by: Daniel Schürmann <daniel at schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9597>

---

 src/amd/compiler/aco_instruction_selection.cpp | 39 ++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index 7684b964c60..5f127b61d35 100644
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -2444,9 +2444,25 @@ void visit_alu_instr(isel_context *ctx, nir_alu_instr *instr)
    case nir_op_i2f32: {
       assert(dst.size() == 1);
       Temp src = get_alu_src(ctx, instr->src[0]);
-      if (instr->src[0].src.ssa->bit_size <= 16)
-         src = convert_int(ctx, bld, src, instr->src[0].src.ssa->bit_size, 32, true);
-      bld.vop1(aco_opcode::v_cvt_f32_i32, Definition(dst), src);
+      const unsigned input_size = instr->src[0].src.ssa->bit_size;
+      if (input_size <= 32) {
+         if (input_size <= 16) {
+            /* Sign-extend to 32-bits */
+            src = convert_int(ctx, bld, src, input_size, 32, true);
+         }
+         bld.vop1(aco_opcode::v_cvt_f32_i32, Definition(dst), src);
+      } else {
+         assert(input_size == 64);
+         RegClass rc = RegClass(src.type(), 1);
+         Temp lower = bld.tmp(rc), upper = bld.tmp(rc);
+         bld.pseudo(aco_opcode::p_split_vector, Definition(lower), Definition(upper), src);
+         lower = bld.vop1(aco_opcode::v_cvt_f64_u32, bld.def(v2), lower);
+         upper = bld.vop1(aco_opcode::v_cvt_f64_i32, bld.def(v2), upper);
+         upper = bld.vop3(aco_opcode::v_ldexp_f64, bld.def(v2), upper, Operand(32u));
+         upper = bld.vop3(aco_opcode::v_add_f64, bld.def(v2), lower, upper);
+         bld.vop1(aco_opcode::v_cvt_f32_f64, Definition(dst), upper);
+      }
+
       break;
    }
    case nir_op_i2f64: {
@@ -2496,12 +2512,23 @@ void visit_alu_instr(isel_context *ctx, nir_alu_instr *instr)
    case nir_op_u2f32: {
       assert(dst.size() == 1);
       Temp src = get_alu_src(ctx, instr->src[0]);
-      if (instr->src[0].src.ssa->bit_size == 8) {
+      const unsigned input_size = instr->src[0].src.ssa->bit_size;
+      if (input_size == 8) {
          bld.vop1(aco_opcode::v_cvt_f32_ubyte0, Definition(dst), src);
-      } else {
-         if (instr->src[0].src.ssa->bit_size == 16)
+      } else if (input_size <= 32) {
+         if (input_size == 16)
             src = convert_int(ctx, bld, src, instr->src[0].src.ssa->bit_size, 32, true);
          bld.vop1(aco_opcode::v_cvt_f32_u32, Definition(dst), src);
+      } else {
+         assert(input_size == 64);
+         RegClass rc = RegClass(src.type(), 1);
+         Temp lower = bld.tmp(rc), upper = bld.tmp(rc);
+         bld.pseudo(aco_opcode::p_split_vector, Definition(lower), Definition(upper), src);
+         lower = bld.vop1(aco_opcode::v_cvt_f64_u32, bld.def(v2), lower);
+         upper = bld.vop1(aco_opcode::v_cvt_f64_u32, bld.def(v2), upper);
+         upper = bld.vop3(aco_opcode::v_ldexp_f64, bld.def(v2), upper, Operand(32u));
+         upper = bld.vop3(aco_opcode::v_add_f64, bld.def(v2), lower, upper);
+         bld.vop1(aco_opcode::v_cvt_f32_f64, Definition(dst), upper);
       }
       break;
    }