[llvm] f0e5f73 - [MachineScheduler] Account for lane masks in basic block liveins

[Jay Foad via llvm-commits]

Author: Jay Foad
Date: 2023-08-15T09:52:43+01:00
New Revision: f0e5f73fdcb2be36bea31bbc67457b82b2e3ed86

URL: https://github.com/llvm/llvm-project/commit/f0e5f73fdcb2be36bea31bbc67457b82b2e3ed86
DIFF: https://github.com/llvm/llvm-project/commit/f0e5f73fdcb2be36bea31bbc67457b82b2e3ed86.diff

LOG: [MachineScheduler] Account for lane masks in basic block liveins

Differential Revision: https://reviews.llvm.org/D157633

Added: 
    

Modified: 
    llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
    llvm/test/CodeGen/AMDGPU/loop-live-out-copy-undef-subrange.ll

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
index d22de53d821fd2..0190fa345eb363 100644
--- a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -223,9 +223,9 @@ void ScheduleDAGInstrs::addSchedBarrierDeps() {
     // uses all the registers that are livein to the successor blocks.
     for (const MachineBasicBlock *Succ : BB->successors()) {
       for (const auto &LI : Succ->liveins()) {
-        // TODO: Use LI.LaneMask to refine this.
-        for (MCRegUnit Unit : TRI->regunits(LI.PhysReg)) {
-          if (!Uses.contains(Unit))
+        for (MCRegUnitMaskIterator U(LI.PhysReg, TRI); U.isValid(); ++U) {
+          auto [Unit, Mask] = *U;
+          if ((Mask & LI.LaneMask).any() && !Uses.contains(Unit))
             Uses.insert(PhysRegSUOper(&ExitSU, -1, Unit));
         }
       }

diff  --git a/llvm/test/CodeGen/AMDGPU/loop-live-out-copy-undef-subrange.ll b/llvm/test/CodeGen/AMDGPU/loop-live-out-copy-undef-subrange.ll
index 6c858efaf37d21..7738ec689dc7eb 100644
--- a/llvm/test/CodeGen/AMDGPU/loop-live-out-copy-undef-subrange.ll
+++ b/llvm/test/CodeGen/AMDGPU/loop-live-out-copy-undef-subrange.ll
@@ -10,9 +10,9 @@ define <3 x float> @liveout_undef_subrange(<3 x float> %arg) {
 ; CHECK:       ; %bb.0: ; %bb
 ; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; CHECK-NEXT:    v_add_f32_e32 v3, v2, v2
-; CHECK-NEXT:    v_add_f32_e32 v0, v0, v0
 ; CHECK-NEXT:    s_mov_b64 s[4:5], 0
 ; CHECK-NEXT:    ; kill: killed $vgpr1
+; CHECK-NEXT:    v_add_f32_e32 v0, v0, v0
 ; CHECK-NEXT:  .LBB0_1: ; %bb1
 ; CHECK-NEXT:    ; =>This Inner Loop Header: Depth=1
 ; CHECK-NEXT:    v_cmp_neq_f32_e32 vcc, 0, v2