Teach getZeroExtendExpr and getSignExtendExpr to use trip-count
information to simplify [sz]ext({a,+,b}) to {zext(a),+,[zs]ext(b)},
as appropriate.
These functions and the trip count code each call into the other, so
this requires careful handling to avoid infinite recursion. During
the initial trip count computation, conservative SCEVs are used,
which are subsequently discarded once the trip count is actually
known.
Among other benefits, this change lets LSR automatically eliminate
some unnecessary zext-inreg and sext-inreg operation where the
operand is an induction variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70241 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/masked-iv-unsafe.ll b/test/CodeGen/X86/masked-iv-unsafe.ll
new file mode 100644
index 0000000..7ccfe85
--- /dev/null
+++ b/test/CodeGen/X86/masked-iv-unsafe.ll
@@ -0,0 +1,386 @@
+; RUN: llvm-as < %s | llc -march=x86-64 > %t
+; RUN: grep and %t | count 6
+; RUN: grep movzb %t | count 6
+; RUN: grep sar %t | count 12
+
+; Don't optimize away zext-inreg and sext-inreg on the loop induction
+; variable, because it isn't safe to do so in these cases.
+
+define void @count_up(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 10, %entry ], [ %indvar.next, %loop ]
+ %indvar.i8 = and i64 %indvar, 255
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %indvar.i24 = and i64 %indvar, 16777215
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = add i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, 0
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @count_down(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 10, %entry ], [ %indvar.next, %loop ]
+ %indvar.i8 = and i64 %indvar, 255
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %indvar.i24 = and i64 %indvar, 16777215
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = sub i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, 20
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @count_up_signed(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 10, %entry ], [ %indvar.next, %loop ]
+ %s0 = shl i64 %indvar, 8
+ %indvar.i8 = ashr i64 %s0, 8
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %s1 = shl i64 %indvar, 24
+ %indvar.i24 = ashr i64 %s1, 24
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = add i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, 0
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @count_down_signed(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 10, %entry ], [ %indvar.next, %loop ]
+ %s0 = shl i64 %indvar, 8
+ %indvar.i8 = ashr i64 %s0, 8
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %s1 = shl i64 %indvar, 24
+ %indvar.i24 = ashr i64 %s1, 24
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = sub i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, 20
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @another_count_up(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 0, %entry ], [ %indvar.next, %loop ]
+ %indvar.i8 = and i64 %indvar, 255
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %indvar.i24 = and i64 %indvar, 16777215
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = add i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, %n
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @another_count_down(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ %n, %entry ], [ %indvar.next, %loop ]
+ %indvar.i8 = and i64 %indvar, 255
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %indvar.i24 = and i64 %indvar, 16777215
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = sub i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, 10
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @another_count_up_signed(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 0, %entry ], [ %indvar.next, %loop ]
+ %s0 = shl i64 %indvar, 8
+ %indvar.i8 = ashr i64 %s0, 8
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %s1 = shl i64 %indvar, 24
+ %indvar.i24 = ashr i64 %s1, 24
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = add i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, %n
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @another_count_down_signed(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ %n, %entry ], [ %indvar.next, %loop ]
+ %s0 = shl i64 %indvar, 8
+ %indvar.i8 = ashr i64 %s0, 8
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %s1 = shl i64 %indvar, 24
+ %indvar.i24 = ashr i64 %s1, 24
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = sub i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, 10
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @yet_another_count_down(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 0, %entry ], [ %indvar.next, %loop ]
+ %indvar.i8 = and i64 %indvar, 255
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %indvar.i24 = and i64 %indvar, 16777215
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = sub i64 %indvar, 1
+ %exitcond = icmp eq i64 %indvar.next, 18446744073709551615
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @yet_another_count_up(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 0, %entry ], [ %indvar.next, %loop ]
+ %indvar.i8 = and i64 %indvar, 255
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %indvar.i24 = and i64 %indvar, 16777215
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = add i64 %indvar, 3
+ %exitcond = icmp eq i64 %indvar.next, 10
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @still_another_count_down(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 10, %entry ], [ %indvar.next, %loop ]
+ %indvar.i8 = and i64 %indvar, 255
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %indvar.i24 = and i64 %indvar, 16777215
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = sub i64 %indvar, 3
+ %exitcond = icmp eq i64 %indvar.next, 0
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @yet_another_count_up_signed(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 0, %entry ], [ %indvar.next, %loop ]
+ %s0 = shl i64 %indvar, 8
+ %indvar.i8 = ashr i64 %s0, 8
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %s1 = shl i64 %indvar, 24
+ %indvar.i24 = ashr i64 %s1, 24
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = add i64 %indvar, 3
+ %exitcond = icmp eq i64 %indvar.next, 10
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+define void @yet_another_count_down_signed(double* %d, i64 %n) nounwind {
+entry:
+ br label %loop
+
+loop:
+ %indvar = phi i64 [ 10, %entry ], [ %indvar.next, %loop ]
+ %s0 = shl i64 %indvar, 8
+ %indvar.i8 = ashr i64 %s0, 8
+ %t0 = getelementptr double* %d, i64 %indvar.i8
+ %t1 = load double* %t0
+ %t2 = mul double %t1, 0.1
+ store double %t2, double* %t0
+ %s1 = shl i64 %indvar, 24
+ %indvar.i24 = ashr i64 %s1, 24
+ %t3 = getelementptr double* %d, i64 %indvar.i24
+ %t4 = load double* %t3
+ %t5 = mul double %t4, 2.3
+ store double %t5, double* %t3
+ %t6 = getelementptr double* %d, i64 %indvar
+ %t7 = load double* %t6
+ %t8 = mul double %t7, 4.5
+ store double %t8, double* %t6
+ %indvar.next = sub i64 %indvar, 3
+ %exitcond = icmp eq i64 %indvar.next, 0
+ br i1 %exitcond, label %return, label %loop
+
+return:
+ ret void
+}
+
+
+