[IndVarSimplify] Fix IndVarSimplify to skip on unfolding predicates when the loop contains control convergence operations.

llvm/lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -31,6 +31,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/iterator_range.h"
+#include "llvm/Analysis/CodeMetrics.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/MemorySSA.h"
@@ -1859,6 +1860,18 @@ bool IndVarSimplify::predicateLoopExits(Loop *L, SCEVExpander &Rewriter) {
         }
       }
 
+  CodeMetrics Metrics;
+  SmallPtrSet<const Value *, 32> EphValues;
+  for (BasicBlock *BB : L->blocks()) {
+    Metrics.analyzeBasicBlock(BB, *TTI, EphValues, /* PrepareForLTO= */ false,
+                              L);
+  }
+
+  if (Metrics.Convergence == ConvergenceKind::ExtendedLoop) {
+    // Do not predicate loops with extended convergence.
+    return false;
+  }
+
   bool Changed = false;
   // Finally, do the actual predication for all predicatable blocks.  A couple
   // of notes here:

llvm/test/Transforms/IndVarSimplify/skip-predication-convergence.ll

@@ -0,0 +1,98 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=indvars -indvars-predicate-loops=1 -S | FileCheck %s
+
+; Loop with body using loop convergence token should be skipped by IndVarSimplify.
+
+%"class.hlsl::RWStructuredBuffer" = type { target("spirv.VulkanBuffer", [0 x i32], 12, 1), target("spirv.VulkanBuffer", i32, 12, 1) }
+
+@_ZL3Out = internal global %"class.hlsl::RWStructuredBuffer" poison, align 8
+@.str = private unnamed_addr constant [4 x i8] c"Out\00", align 1
+
+declare token @llvm.experimental.convergence.entry() #0
+
+define void @loop() local_unnamed_addr #1 {
+; CHECK-LABEL: @loop(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = tail call token @llvm.experimental.convergence.entry()
+; CHECK-NEXT:    [[TMP1:%.*]] = tail call target("spirv.VulkanBuffer", [0 x i32], 12, 1) @llvm.spv.resource.handlefrombinding.tspirv.VulkanBuffer_a0i32_12_1t(i32 0, i32 0, i32 1, i32 0, ptr nonnull @.str)
+; CHECK-NEXT:    [[TMP2:%.*]] = tail call target("spirv.VulkanBuffer", i32, 12, 1) @llvm.spv.resource.counterhandlefromimplicitbinding.tspirv.VulkanBuffer_i32_12_1t.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) [[TMP1]], i32 0, i32 0)
+; CHECK-NEXT:    store target("spirv.VulkanBuffer", [0 x i32], 12, 1) [[TMP1]], ptr @_ZL3Out, align 8
+; CHECK-NEXT:    store target("spirv.VulkanBuffer", i32, 12, 1) [[TMP2]], ptr getelementptr inbounds nuw (i8, ptr @_ZL3Out, i64 8), align 8
+; CHECK-NEXT:    [[TMP3:%.*]] = tail call i32 @llvm.spv.thread.id.in.group.i32(i32 0)
+; CHECK-NEXT:    br label [[FOR_COND_I:%.*]]
+; CHECK:       for.cond.i:
+; CHECK-NEXT:    [[I_0_I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC_I:%.*]], [[FOR_BODY_I:%.*]] ]
+; CHECK-NEXT:    [[TMP4:%.*]] = call token @llvm.experimental.convergence.loop() [ "convergencectrl"(token [[TMP0]]) ]
+; CHECK-NEXT:    [[CMP_I:%.*]] = icmp ult i32 [[I_0_I]], 8
+; CHECK-NEXT:    br i1 [[CMP_I]], label [[FOR_BODY_I]], label [[_Z4LOOPDV3_J_EXIT_LOOPEXIT:%.*]]
+; CHECK:       for.body.i:
+; CHECK-NEXT:    [[CMP1_I:%.*]] = icmp eq i32 [[I_0_I]], [[TMP3]]
+; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I_0_I]], 1
+; CHECK-NEXT:    br i1 [[CMP1_I]], label [[IF_THEN_I:%.*]], label [[FOR_COND_I]]
+; CHECK:       _Z4loopDv3_j.exit.loopexit:
+; CHECK-NEXT:    br label [[_Z4LOOPDV3_J_EXIT:%.*]]
+; CHECK:       if.then.i:
+; CHECK-NEXT:    [[HLSL_WAVE_ACTIVE_MAX2_I:%.*]] = call spir_func i32 @llvm.spv.wave.reduce.umax.i32(i32 [[TMP3]]) [ "convergencectrl"(token [[TMP4]]) ]
+; CHECK-NEXT:    [[TMP5:%.*]] = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) [[TMP1]], i32 [[TMP3]])
+; CHECK-NEXT:    store i32 [[HLSL_WAVE_ACTIVE_MAX2_I]], ptr addrspace(11) [[TMP5]], align 4
+; CHECK-NEXT:    br label [[_Z4LOOPDV3_J_EXIT]]
+; CHECK:       _Z4loopDv3_j.exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = tail call token @llvm.experimental.convergence.entry()
+  %1 = tail call target("spirv.VulkanBuffer", [0 x i32], 12, 1) @llvm.spv.resource.handlefrombinding.tspirv.VulkanBuffer_a0i32_12_1t(i32 0, i32 0, i32 1, i32 0, ptr nonnull @.str)
+  %2 = tail call target("spirv.VulkanBuffer", i32, 12, 1) @llvm.spv.resource.counterhandlefromimplicitbinding.tspirv.VulkanBuffer_i32_12_1t.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) %1, i32 0, i32 0)
+  store target("spirv.VulkanBuffer", [0 x i32], 12, 1) %1, ptr @_ZL3Out, align 8
+  store target("spirv.VulkanBuffer", i32, 12, 1) %2, ptr getelementptr inbounds nuw (i8, ptr @_ZL3Out, i64 8), align 8
+  %3 = tail call i32 @llvm.spv.thread.id.in.group.i32(i32 0)
+  br label %for.cond.i
+
+; Loop:
+for.cond.i:                                       ; preds = %for.body.i, %entry
+  %i.0.i = phi i32 [ 0, %entry ], [ %inc.i, %for.body.i ]
+  %4 = call token @llvm.experimental.convergence.loop() [ "convergencectrl"(token %0) ]
+  %cmp.i = icmp ult i32 %i.0.i, 8
+  br i1 %cmp.i, label %for.body.i, label %_Z4loopDv3_j.exit.loopexit
+
+for.body.i:                                       ; preds = %for.cond.i
+  %cmp1.i = icmp eq i32 %i.0.i, %3
+  %inc.i = add nuw nsw i32 %i.0.i, 1
+  br i1 %cmp1.i, label %if.then.i, label %for.cond.i
+
+; Exit blocks
+_Z4loopDv3_j.exit.loopexit:                       ; preds = %for.cond.i
+  br label %_Z4loopDv3_j.exit
+
+if.then.i:                                        ; preds = %for.body.i
+  %hlsl.wave.active.max2.i = call spir_func i32 @llvm.spv.wave.reduce.umax.i32(i32 %3) [ "convergencectrl"(token %4) ]
+  %5 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) %1, i32 %3)
+  store i32 %hlsl.wave.active.max2.i, ptr addrspace(11) %5, align 4
+  br label %_Z4loopDv3_j.exit
+
+_Z4loopDv3_j.exit:                                ; preds = %_Z4loopDv3_j.exit.loopexit, %if.then.i
+  ret void
+}
+
+; Function Attrs: mustprogress nofree nosync nounwind willreturn memory(none)
+declare i32 @llvm.spv.thread.id.in.group.i32(i32) #2
+
+; Function Attrs: convergent mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare token @llvm.experimental.convergence.loop() #0
+
+; Function Attrs: convergent mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare i32 @llvm.spv.wave.reduce.umax.i32(i32) #0
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare target("spirv.VulkanBuffer", [0 x i32], 12, 1) @llvm.spv.resource.handlefrombinding.tspirv.VulkanBuffer_a0i32_12_1t(i32, i32, i32, i32, ptr) #4
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare target("spirv.VulkanBuffer", i32, 12, 1) @llvm.spv.resource.counterhandlefromimplicitbinding.tspirv.VulkanBuffer_i32_12_1t.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1), i32, i32) #4
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1), i32) #4
+
+attributes #0 = { convergent mustprogress nocallback nofree nosync nounwind willreturn memory(none) }
+attributes #1 = { convergent noinline norecurse "frame-pointer"="all" "hlsl.numthreads"="8,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #2 = { mustprogress nofree nosync nounwind willreturn memory(none) }
+attributes #4 = { mustprogress nocallback nofree nosync nounwind willreturn memory(none) }

llvm/test/Transforms/IndVarSimplify/skip-predictaion-nested-convergence.ll

@@ -0,0 +1,139 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=indvars -indvars-predicate-loops=1 -S | FileCheck %s
+
+; Nested loops with body using loop convergence token should be skipped by IndVarSimplify.
+
+%"class.hlsl::RWStructuredBuffer" = type { target("spirv.VulkanBuffer", [0 x i32], 12, 1), target("spirv.VulkanBuffer", i32, 12, 1) }
+
+@_ZL3Out = internal global %"class.hlsl::RWStructuredBuffer" poison, align 8
+@.str = private unnamed_addr constant [4 x i8] c"Out\00", align 1
+
+; Function Attrs: convergent mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare token @llvm.experimental.convergence.entry() #0
+
+define void @nested() local_unnamed_addr #1 {
+; CHECK-LABEL: @nested(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = tail call token @llvm.experimental.convergence.entry()
+; CHECK-NEXT:    [[TMP1:%.*]] = tail call target("spirv.VulkanBuffer", [0 x i32], 12, 1) @llvm.spv.resource.handlefrombinding.tspirv.VulkanBuffer_a0i32_12_1t(i32 0, i32 0, i32 1, i32 0, ptr nonnull @.str)
+; CHECK-NEXT:    [[TMP2:%.*]] = tail call target("spirv.VulkanBuffer", i32, 12, 1) @llvm.spv.resource.counterhandlefromimplicitbinding.tspirv.VulkanBuffer_i32_12_1t.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) [[TMP1]], i32 0, i32 0)
+; CHECK-NEXT:    store target("spirv.VulkanBuffer", [0 x i32], 12, 1) [[TMP1]], ptr @_ZL3Out, align 8
+; CHECK-NEXT:    store target("spirv.VulkanBuffer", i32, 12, 1) [[TMP2]], ptr getelementptr inbounds nuw (i8, ptr @_ZL3Out, i64 8), align 8
+; CHECK-NEXT:    [[TMP3:%.*]] = tail call i32 @llvm.spv.thread.id.in.group.i32(i32 0)
+; CHECK-NEXT:    [[TMP4:%.*]] = tail call i32 @llvm.spv.thread.id.in.group.i32(i32 1)
+; CHECK-NEXT:    [[MUL_I:%.*]] = shl nuw nsw i32 [[TMP3]], 3
+; CHECK-NEXT:    [[ADD_I:%.*]] = add nuw nsw i32 [[MUL_I]], [[TMP4]]
+; CHECK-NEXT:    br label [[FOR_COND_I:%.*]]
+; CHECK:       for.cond.i:
+; CHECK-NEXT:    [[I_0_I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC10_I:%.*]], [[CLEANUP_I:%.*]] ]
+; CHECK-NEXT:    [[TMP5:%.*]] = call token @llvm.experimental.convergence.loop() [ "convergencectrl"(token [[TMP0]]) ]
+; CHECK-NEXT:    [[CMP_I:%.*]] = icmp ult i32 [[I_0_I]], 8
+; CHECK-NEXT:    br i1 [[CMP_I]], label [[FOR_COND1_I_PREHEADER:%.*]], label [[_Z4NESTEDDV3_J_EXIT:%.*]]
+; CHECK:       for.cond1.i.preheader:
+; CHECK-NEXT:    [[CMP5_I:%.*]] = icmp eq i32 [[I_0_I]], [[TMP3]]
+; CHECK-NEXT:    br label [[FOR_COND1_I:%.*]]
+; CHECK:       for.cond1.i:
+; CHECK-NEXT:    [[J_0_I:%.*]] = phi i32 [ [[INC_I:%.*]], [[FOR_BODY4_I:%.*]] ], [ 0, [[FOR_COND1_I_PREHEADER]] ]
+; CHECK-NEXT:    [[TMP6:%.*]] = call token @llvm.experimental.convergence.loop() [ "convergencectrl"(token [[TMP5]]) ]
+; CHECK-NEXT:    [[CMP2_I:%.*]] = icmp ult i32 [[J_0_I]], 8
+; CHECK-NEXT:    br i1 [[CMP2_I]], label [[FOR_BODY4_I]], label [[CLEANUP_I_LOOPEXIT:%.*]]
+; CHECK:       for.body4.i:
+; CHECK-NEXT:    [[CMP6_I:%.*]] = icmp eq i32 [[J_0_I]], [[TMP4]]
+; CHECK-NEXT:    [[OR_COND:%.*]] = select i1 [[CMP5_I]], i1 [[CMP6_I]], i1 false
+; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[J_0_I]], 1
+; CHECK-NEXT:    br i1 [[OR_COND]], label [[IF_THEN_I:%.*]], label [[FOR_COND1_I]]
+; CHECK:       cleanup.i.loopexit:
+; CHECK-NEXT:    br label [[CLEANUP_I]]
+; CHECK:       if.then.i:
+; CHECK-NEXT:    [[HLSL_WAVE_ACTIVE_MAX7_I:%.*]] = call spir_func i32 @llvm.spv.wave.reduce.umax.i32(i32 [[ADD_I]]) [ "convergencectrl"(token [[TMP6]]) ]
+; CHECK-NEXT:    [[TMP7:%.*]] = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) [[TMP1]], i32 [[ADD_I]])
+; CHECK-NEXT:    store i32 [[HLSL_WAVE_ACTIVE_MAX7_I]], ptr addrspace(11) [[TMP7]], align 4
+; CHECK-NEXT:    br label [[CLEANUP_I]]
+; CHECK:       cleanup.i:
+; CHECK-NEXT:    [[INC10_I]] = add nuw nsw i32 [[I_0_I]], 1
+; CHECK-NEXT:    br label [[FOR_COND_I]]
+; CHECK:       _Z4nestedDv3_j.exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = tail call token @llvm.experimental.convergence.entry()
+  %1 = tail call target("spirv.VulkanBuffer", [0 x i32], 12, 1) @llvm.spv.resource.handlefrombinding.tspirv.VulkanBuffer_a0i32_12_1t(i32 0, i32 0, i32 1, i32 0, ptr nonnull @.str)
+  %2 = tail call target("spirv.VulkanBuffer", i32, 12, 1) @llvm.spv.resource.counterhandlefromimplicitbinding.tspirv.VulkanBuffer_i32_12_1t.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) %1, i32 0, i32 0)
+  store target("spirv.VulkanBuffer", [0 x i32], 12, 1) %1, ptr @_ZL3Out, align 8
+  store target("spirv.VulkanBuffer", i32, 12, 1) %2, ptr getelementptr inbounds nuw (i8, ptr @_ZL3Out, i64 8), align 8
+  %3 = tail call i32 @llvm.spv.thread.id.in.group.i32(i32 0)
+  %4 = tail call i32 @llvm.spv.thread.id.in.group.i32(i32 1)
+  %mul.i = shl nuw nsw i32 %3, 3
+  %add.i = add nuw nsw i32 %mul.i, %4
+  br label %for.cond.i
+
+for.cond.i:                                       ; preds = %cleanup.i, %entry
+  %i.0.i = phi i32 [ 0, %entry ], [ %inc10.i, %cleanup.i ]
+  %5 = call token @llvm.experimental.convergence.loop() [ "convergencectrl"(token %0) ]
+  %cmp.i = icmp ult i32 %i.0.i, 8
+  br i1 %cmp.i, label %for.cond1.i.preheader, label %_Z4nestedDv3_j.exit
+
+; Preheader:
+for.cond1.i.preheader:                            ; preds = %for.cond.i
+  %cmp5.i = icmp eq i32 %i.0.i, %3
+  br label %for.cond1.i
+
+; Loop:
+for.cond1.i:                                      ; preds = %for.body4.i, %for.cond1.i.preheader
+  %j.0.i = phi i32 [ %inc.i, %for.body4.i ], [ 0, %for.cond1.i.preheader ]
+  %6 = call token @llvm.experimental.convergence.loop() [ "convergencectrl"(token %5) ]
+  %cmp2.i = icmp ult i32 %j.0.i, 8
+  br i1 %cmp2.i, label %for.body4.i, label %cleanup.i.loopexit
+
+for.body4.i:                                      ; preds = %for.cond1.i
+  %cmp6.i = icmp eq i32 %j.0.i, %4
+  %or.cond = select i1 %cmp5.i, i1 %cmp6.i, i1 false
+  %inc.i = add nuw nsw i32 %j.0.i, 1
+  br i1 %or.cond, label %if.then.i, label %for.cond1.i
+
+; Exit blocks
+cleanup.i.loopexit:                               ; preds = %for.cond1.i
+  br label %cleanup.i
+
+if.then.i:                                        ; preds = %for.body4.i
+  %hlsl.wave.active.max7.i = call spir_func i32 @llvm.spv.wave.reduce.umax.i32(i32 %add.i) [ "convergencectrl"(token %6) ]
+  %7 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) %1, i32 %add.i)
+  store i32 %hlsl.wave.active.max7.i, ptr addrspace(11) %7, align 4
+  br label %cleanup.i
+
+cleanup.i:                                        ; preds = %cleanup.i.loopexit, %if.then.i
+  %inc10.i = add nuw nsw i32 %i.0.i, 1
+  br label %for.cond.i
+
+_Z4nestedDv3_j.exit:                                ; preds = %for.cond.i
+  ret void
+}
+
+; Function Attrs: mustprogress nofree nosync nounwind willreturn memory(none)
+declare i32 @llvm.spv.thread.id.in.group.i32(i32) #2
+
+; Function Attrs: convergent mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare token @llvm.experimental.convergence.loop() #0
+
+; Function Attrs: convergent mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare i32 @llvm.spv.wave.reduce.umax.i32(i32) #0
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare target("spirv.VulkanBuffer", [0 x i32], 12, 1) @llvm.spv.resource.handlefrombinding.tspirv.VulkanBuffer_a0i32_12_1t(i32, i32, i32, i32, ptr) #4
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare target("spirv.VulkanBuffer", i32, 12, 1) @llvm.spv.resource.counterhandlefromimplicitbinding.tspirv.VulkanBuffer_i32_12_1t.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1), i32, i32) #4
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(none)
+declare ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1), i32) #4
+
+; Function Attrs: nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: readwrite)
+declare void @llvm.experimental.noalias.scope.decl(metadata) #5
+
+attributes #0 = { convergent mustprogress nocallback nofree nosync nounwind willreturn memory(none) }
+attributes #1 = { convergent noinline norecurse "frame-pointer"="all" "hlsl.numthreads"="8,8,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #2 = { mustprogress nofree nosync nounwind willreturn memory(none) }
+attributes #3 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+attributes #4 = { mustprogress nocallback nofree nosync nounwind willreturn memory(none) }
+attributes #5 = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: readwrite) }
+attributes #6 = { nounwind }