Mesa (master): aco: don't split live-ranges of linear VGPRs

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Module: Mesa
Branch: master
Commit: 8861a82be7df2a5816254b45d390ddafad7d8711
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=8861a82be7df2a5816254b45d390ddafad7d8711

Author: Daniel Schürmann <daniel at schuermann.dev>
Date:   Fri Nov 29 16:43:24 2019 +0100

aco: don't split live-ranges of linear VGPRs

Fixes: 93c8ebfa780ebd1495095e794731881aef29e7d3 'aco: Initial commit of independent AMD compiler'

Reviewed-by: Rhys Perry <pendingchaos02 at gmail.com>

---

 src/amd/compiler/aco_register_allocation.cpp | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/amd/compiler/aco_register_allocation.cpp b/src/amd/compiler/aco_register_allocation.cpp
index c90c91a0325..c4144cc42f0 100644
--- a/src/amd/compiler/aco_register_allocation.cpp
+++ b/src/amd/compiler/aco_register_allocation.cpp
@@ -759,11 +759,18 @@ PhysReg get_reg_create_vector(ra_ctx& ctx,
 
       /* count variables to be moved and check war_hint */
       bool war_hint = false;
-      for (unsigned j = reg_lo; j <= reg_hi; j++) {
-         if (reg_file[j] != 0)
+      bool linear_vgpr = false;
+      for (unsigned j = reg_lo; j <= reg_hi && !linear_vgpr; j++) {
+         if (reg_file[j] != 0) {
             k++;
+            /* we cannot split live ranges of linear vgprs */
+            if (ctx.assignments[reg_file[j]].second & (1 << 6))
+               linear_vgpr = true;
+         }
          war_hint |= ctx.war_hint[j];
       }
+      if (linear_vgpr || (war_hint && !best_war_hint))
+         continue;
 
       /* count operands in wrong positions */
       for (unsigned j = 0, offset = 0; j < instr->operands.size(); offset += instr->operands[j].size(), j++) {
@@ -775,7 +782,7 @@ PhysReg get_reg_create_vector(ra_ctx& ctx,
             k += instr->operands[j].size();
       }
       bool aligned = rc == RegClass::v4 && reg_lo % 4 == 0;
-      if (k > num_moves || (!aligned && k == num_moves) || (war_hint && !best_war_hint))
+      if (k > num_moves || (!aligned && k == num_moves))
          continue;
 
       best_pos = reg_lo;
@@ -961,7 +968,7 @@ void register_allocation(Program *program, std::vector<std::set<Temp>> live_out_
 
    handle_live_in = [&](Temp val, Block *block) -> Temp {
       std::vector<unsigned>& preds = val.is_linear() ? block->linear_preds : block->logical_preds;
-      if (preds.size() == 0 && block->index != 0) {
+      if (preds.size() == 0 || val.regClass() == val.regClass().as_linear()) {
          renames[block->index][val.id()] = val;
          return val;
       }