[llvm] [SVE] Wide active lane mask (PR #76514)

[Momchil Velikov via llvm-commits]

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@@ -18,102 +18,106 @@ define void @simple_memset(i32 %val, ptr %ptr, i64 %n) #0 {
 ; CHECK-NEXT:    [[N_RND_UP:%.*]] = add i64 [[UMAX]], [[TMP4]]
 ; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[N_RND_UP]], [[TMP1]]
 ; CHECK-NEXT:    [[N_VEC:%.*]] = sub i64 [[N_RND_UP]], [[N_MOD_VF]]
-; CHECK-NEXT:    [[TMP61:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT:    [[TMP62:%.*]] = mul i64 [[TMP61]], 16
 ; CHECK-NEXT:    [[TMP5:%.*]] = call i64 @llvm.vscale.i64()
 ; CHECK-NEXT:    [[TMP6:%.*]] = mul i64 [[TMP5]], 16
-; CHECK-NEXT:    [[TMP7:%.*]] = sub i64 [[UMAX]], [[TMP6]]
-; CHECK-NEXT:    [[TMP8:%.*]] = icmp ugt i64 [[UMAX]], [[TMP6]]
-; CHECK-NEXT:    [[TMP9:%.*]] = select i1 [[TMP8]], i64 [[TMP7]], i64 0
-; CHECK-NEXT:    [[TMP10:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT:    [[TMP11:%.*]] = mul i64 [[TMP10]], 16
-; CHECK-NEXT:    [[TMP12:%.*]] = sub i64 [[UMAX]], [[TMP11]]
-; CHECK-NEXT:    [[TMP13:%.*]] = icmp ugt i64 [[UMAX]], [[TMP11]]
-; CHECK-NEXT:    [[TMP14:%.*]] = select i1 [[TMP13]], i64 [[TMP12]], i64 0
-; CHECK-NEXT:    [[TMP15:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT:    [[TMP16:%.*]] = mul i64 [[TMP15]], 16
-; CHECK-NEXT:    [[TMP17:%.*]] = sub i64 [[UMAX]], [[TMP16]]
-; CHECK-NEXT:    [[TMP18:%.*]] = icmp ugt i64 [[UMAX]], [[TMP16]]
-; CHECK-NEXT:    [[TMP19:%.*]] = select i1 [[TMP18]], i64 [[TMP17]], i64 0
-; CHECK-NEXT:    [[TMP20:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT:    [[TMP21:%.*]] = mul i64 [[TMP20]], 16
-; CHECK-NEXT:    [[TMP22:%.*]] = sub i64 [[UMAX]], [[TMP21]]
-; CHECK-NEXT:    [[TMP23:%.*]] = icmp ugt i64 [[UMAX]], [[TMP21]]
-; CHECK-NEXT:    [[TMP24:%.*]] = select i1 [[TMP23]], i64 [[TMP22]], i64 0
-; CHECK-NEXT:    [[TMP25:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT:    [[TMP26:%.*]] = mul i64 [[TMP25]], 4
-; CHECK-NEXT:    [[INDEX_PART_NEXT:%.*]] = add i64 0, [[TMP26]]
+; CHECK-NEXT:    [[TMP7:%.*]] = call i64 @llvm.vscale.i64()
+; CHECK-NEXT:    [[TMP8:%.*]] = mul i64 [[TMP7]], 16
+; CHECK-NEXT:    [[TMP9:%.*]] = sub i64 [[UMAX]], [[TMP8]]
+; CHECK-NEXT:    [[TMP10:%.*]] = icmp ugt i64 [[UMAX]], [[TMP8]]
+; CHECK-NEXT:    [[TMP11:%.*]] = select i1 [[TMP10]], i64 [[TMP9]], i64 0
+; CHECK-NEXT:    [[TMP12:%.*]] = call i64 @llvm.vscale.i64()
+; CHECK-NEXT:    [[TMP13:%.*]] = mul i64 [[TMP12]], 16
+; CHECK-NEXT:    [[TMP14:%.*]] = sub i64 [[UMAX]], [[TMP13]]
+; CHECK-NEXT:    [[TMP15:%.*]] = icmp ugt i64 [[UMAX]], [[TMP13]]
+; CHECK-NEXT:    [[TMP16:%.*]] = select i1 [[TMP15]], i64 [[TMP14]], i64 0
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momchil-velikov wrote:

It will remove them in the InstructionCombiner or one of the many places the compiler calls `llvm::RecursivelyDeleteTriviallyDeadInstructions` (I think it's the former).

https://github.com/llvm/llvm-project/pull/76514