[MachinePipeliner] Fix II_setByPragma initialization

[alonkom]

Summary

II_setByPragma was not reset between 2 calls of the MachinePipleiner pass

[bcahoon]

Hi Alon, Thanks for the patch!

[alonkom]

I'm having Github commit permission issues so I would appreciate if someone can submit it on behalf of me

llvm/lib/CodeGen/MachinePipeliner.cpp

#endif
   Changed = swingModuloScheduler(L);
 
   return Changed;
 }
 
 void MachinePipeliner::setPragmaPipelineOptions(MachineLoop &L) {
   // Reset the pragma for the next loop in iteration.
   disabledByPragma = false;
+  II_setByPragma = 0;
 
   MachineBasicBlock *LBLK = L.getTopBlock();
 
   if (LBLK == nullptr)
     return;
 
   const BasicBlock *BBLK = LBLK->getBasicBlock();
   if (BBLK == nullptr)

llvm/test/CodeGen/Hexagon/swp-pragma-initiation-interval-reset.ii

+; RUN: llc -disable-lsr -march=hexagon -enable-pipeliner  \
+; RUN:     -debug-only=pipeliner < %s 2>&1 > /dev/null -pipeliner-experimental-cg=true | FileCheck %s
+; REQUIRES: asserts
+;
+; Test that checks that the II set by pragma was reset between loops.
+
+; CHECK: MII = 10 MAX_II = 10
+; CHECK: MII = 1 MAX_II = 11 (rec=1, res=1)
+; CHECK-NOT: MII = 10 MAX_II = 10
+
+; Function Attrs: nounwind
+define void @f0(i32* nocapture %a0, i32 %a1) #0 {
+b0:
+  %v0 = icmp sgt i32 %a1, 1
+  br i1 %v0, label %b1, label %b4
+
+b1:                                               ; preds = %b0
+  %v1 = load i32, i32* %a0, align 4
+  %v2 = add i32 %v1, 10
+  %v3 = getelementptr i32, i32* %a0, i32 1
+  %v4 = add i32 %a1, -1
+  br label %b2
+
+b2:                                               ; preds = %b2, %b1
+  %v5 = phi i32 [ %v12, %b2 ], [ %v4, %b1 ]
+  %v6 = phi i32* [ %v11, %b2 ], [ %v3, %b1 ]
+  %v7 = phi i32 [ %v10, %b2 ], [ %v2, %b1 ]
+  store i32 %v7, i32* %v6, align 4
+  %v8 = add i32 %v7, 10
+  %v9 = getelementptr i32, i32* %v6, i32 -1
+  store i32 %v8, i32* %v9, align 4
+  %v10 = add i32 %v7, 10
+  %v11 = getelementptr i32, i32* %v6, i32 1
+  %v12 = add i32 %v5, -1
+  %v13 = icmp eq i32 %v12, 0
+  br i1 %v13, label %b3, label %b2
+
+b3:                                               ; preds = %b2
+  br label %b4 , !llvm.loop !2
+
+b4:                                               ; preds = %b3, %b0
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @f1(i32* nocapture %a0, i32 %a1) #0 {
+b0:
+  %v0 = icmp sgt i32 %a1, 1
+  br i1 %v0, label %b1, label %b4
+
+b1:                                               ; preds = %b0
+  %v1 = load i32, i32* %a0, align 4
+  %v2 = add i32 %v1, 10
+  %v3 = getelementptr i32, i32* %a0, i32 1
+  %v4 = add i32 %a1, -1
+  br label %b2
+
+b2:                                               ; preds = %b2, %b1
+  %v5 = phi i32 [ %v12, %b2 ], [ %v4, %b1 ]
+  %v6 = phi i32* [ %v11, %b2 ], [ %v3, %b1 ]
+  %v7 = phi i32 [ %v10, %b2 ], [ %v2, %b1 ]
+  store i32 %v7, i32* %v6, align 4
+  %v8 = add i32 %v7, 10
+  %v9 = getelementptr i32, i32* %v6, i32 -1
+  store i32 %v8, i32* %v9, align 4
+  %v10 = add i32 %v7, 10
+  %v11 = getelementptr i32, i32* %v6, i32 1
+  %v12 = add i32 %v5, -1
+  %v13 = icmp eq i32 %v12, 0
+  br i1 %v13, label %b3, label %b2
+
+b3:                                               ; preds = %b2
+  br label %b4
+
+b4:                                               ; preds = %b3, %b0
+  ret void
+}
+
+attributes #0 = { nounwind }
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{!2, !2, i64 0}
+!2 = distinct !{!2, !3}
+!3 = !{!"llvm.loop.pipeline.initiationinterval", i32 10}
+