[InstCombine / InstSimplify] add and move tests for lshr transforms; NFC

llvm-svn: 291970

3 files changed, 146 insertions, 22 deletions

diff --git a/llvm/test/Transforms/InstCombine/intrinsics.ll b/llvm/test/Transforms/InstCombine/intrinsics.ll
index 858f9c029b3..e8f5ddd329f 100644
--- a/llvm/test/Transforms/InstCombine/intrinsics.ll
+++ b/llvm/test/Transforms/InstCombine/intrinsics.ll
@@ -351,33 +351,12 @@ define void @ctpop_cmp_vec(<2 x i32> %a, <2 x i1>* %b) {
 ; CHECK-NEXT: store volatile <2 x i1> %pop1.cmp, <2 x i1>* %b
 }
 
-define i32 @cttz_simplify1a(i32 %x) nounwind readnone ssp {
-  %tmp1 = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
-  %shr3 = lshr i32 %tmp1, 5
-  ret i32 %shr3
-
-; CHECK-LABEL: @cttz_simplify1a(
-; CHECK: icmp eq i32 %x, 0
-; CHECK-NEXT: zext i1
-; CHECK-NEXT: ret i32
-}
-
-define i32 @cttz_simplify1b(i32 %x) nounwind readnone ssp {
-  %tmp1 = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true)
-  %shr3 = lshr i32 %tmp1, 5
-  ret i32 %shr3
-
-; CHECK-LABEL: @cttz_simplify1b(
-; CHECK-NEXT: ret i32 0
-}
-
-define i32 @ctlz_undef(i32 %Value) nounwind {
+define i32 @ctlz_undef(i32 %Value) {
 ; CHECK-LABEL: @ctlz_undef(
 ; CHECK-NEXT:    ret i32 undef
 ;
   %ctlz = call i32 @llvm.ctlz.i32(i32 0, i1 true)
   ret i32 %ctlz
-
 }
 
 define i32 @ctlz_make_undef(i32 %a) {
diff --git a/llvm/test/Transforms/InstCombine/lshr.ll b/llvm/test/Transforms/InstCombine/lshr.ll
new file mode 100644
index 00000000000..13aa5e7dc09
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/lshr.ll
@@ -0,0 +1,102 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -instcombine -S < %s | FileCheck %s
+
+declare i32 @llvm.cttz.i32(i32, i1) nounwind readnone
+declare i32 @llvm.ctlz.i32(i32, i1) nounwind readnone
+declare i32 @llvm.ctpop.i32(i32) nounwind readnone
+declare <2 x i8> @llvm.cttz.v2i8(<2 x i8>, i1) nounwind readnone
+declare <2 x i8> @llvm.ctlz.v2i8(<2 x i8>, i1) nounwind readnone
+declare <2 x i8> @llvm.ctpop.v2i8(<2 x i8>) nounwind readnone
+
+define i32 @lshr_ctlz_zero_is_not_undef(i32 %x) {
+; CHECK-LABEL: @lshr_ctlz_zero_is_not_undef(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 %x, 0
+; CHECK-NEXT:    [[SH:%.*]] = zext i1 [[TMP1]] to i32
+; CHECK-NEXT:    ret i32 [[SH]]
+;
+  %ct = call i32 @llvm.ctlz.i32(i32 %x, i1 false)
+  %sh = lshr i32 %ct, 5
+  ret i32 %sh
+}
+
+define i32 @lshr_cttz_zero_is_not_undef(i32 %x) {
+; CHECK-LABEL: @lshr_cttz_zero_is_not_undef(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 %x, 0
+; CHECK-NEXT:    [[SH:%.*]] = zext i1 [[TMP1]] to i32
+; CHECK-NEXT:    ret i32 [[SH]]
+;
+  %ct = call i32 @llvm.cttz.i32(i32 %x, i1 false)
+  %sh = lshr i32 %ct, 5
+  ret i32 %sh
+}
+
+define i32 @lshr_ctpop(i32 %x) {
+; CHECK-LABEL: @lshr_ctpop(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 %x, -1
+; CHECK-NEXT:    [[SH:%.*]] = zext i1 [[TMP1]] to i32
+; CHECK-NEXT:    ret i32 [[SH]]
+;
+  %ct = call i32 @llvm.ctpop.i32(i32 %x)
+  %sh = lshr i32 %ct, 5
+  ret i32 %sh
+}
+
+define <2 x i8> @lshr_ctlz_zero_is_not_undef_splat_vec(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_ctlz_zero_is_not_undef_splat_vec(
+; CHECK-NEXT:    [[CT:%.*]] = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 false)
+; CHECK-NEXT:    [[SH:%.*]] = lshr <2 x i8> [[CT]], <i8 3, i8 3>
+; CHECK-NEXT:    ret <2 x i8> [[SH]]
+;
+  %ct = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 false)
+  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
+  ret <2 x i8> %sh
+}
+
+define <2 x i8> @lshr_cttz_zero_is_not_undef_splat_vec(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_cttz_zero_is_not_undef_splat_vec(
+; CHECK-NEXT:    [[CT:%.*]] = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 false)
+; CHECK-NEXT:    [[SH:%.*]] = lshr <2 x i8> [[CT]], <i8 3, i8 3>
+; CHECK-NEXT:    ret <2 x i8> [[SH]]
+;
+  %ct = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 false)
+  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
+  ret <2 x i8> %sh
+}
+
+define <2 x i8> @lshr_ctpop_splat_vec(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_ctpop_splat_vec(
+; CHECK-NEXT:    [[CT:%.*]] = call <2 x i8> @llvm.ctpop.v2i8(<2 x i8> %x)
+; CHECK-NEXT:    [[SH:%.*]] = lshr <2 x i8> [[CT]], <i8 3, i8 3>
+; CHECK-NEXT:    ret <2 x i8> [[SH]]
+;
+  %ct = call <2 x i8> @llvm.ctpop.v2i8(<2 x i8> %x)
+  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
+  ret <2 x i8> %sh
+}
+
+define i8 @lshr_exact(i8 %x) {
+; CHECK-LABEL: @lshr_exact(
+; CHECK-NEXT:    [[SHL:%.*]] = shl i8 %x, 2
+; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[SHL]], 4
+; CHECK-NEXT:    [[LSHR:%.*]] = lshr exact i8 [[ADD]], 2
+; CHECK-NEXT:    ret i8 [[LSHR]]
+;
+  %shl = shl i8 %x, 2
+  %add = add i8 %shl, 4
+  %lshr = lshr i8 %add, 2
+  ret i8 %lshr
+}
+
+define <2 x i8> @lshr_exact_splat_vec(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_exact_splat_vec(
+; CHECK-NEXT:    [[SHL:%.*]] = shl <2 x i8> %x, <i8 2, i8 2>
+; CHECK-NEXT:    [[ADD:%.*]] = add <2 x i8> [[SHL]], <i8 4, i8 4>
+; CHECK-NEXT:    [[LSHR:%.*]] = lshr <2 x i8> [[ADD]], <i8 2, i8 2>
+; CHECK-NEXT:    ret <2 x i8> [[LSHR]]
+;
+  %shl = shl <2 x i8> %x, <i8 2, i8 2>
+  %add = add <2 x i8> %shl, <i8 4, i8 4>
+  %lshr = lshr <2 x i8> %add, <i8 2, i8 2>
+  ret <2 x i8> %lshr
+}
+
diff --git a/llvm/test/Transforms/InstSimplify/shift-knownbits.ll b/llvm/test/Transforms/InstSimplify/shift-knownbits.ll
index f50ea0582c6..63b9b76fd22 100644
--- a/llvm/test/Transforms/InstSimplify/shift-knownbits.ll
+++ b/llvm/test/Transforms/InstSimplify/shift-knownbits.ll
@@ -145,3 +145,46 @@ define i1 @shl_i1(i1 %a, i1 %b) {
   ret i1 %shl
 }
 
+; Simplify count leading/trailing zeros to zero if all valid bits are shifted out.
+
+declare i32 @llvm.cttz.i32(i32, i1) nounwind readnone
+declare i32 @llvm.ctlz.i32(i32, i1) nounwind readnone
+declare <2 x i8> @llvm.cttz.v2i8(<2 x i8>, i1) nounwind readnone
+declare <2 x i8> @llvm.ctlz.v2i8(<2 x i8>, i1) nounwind readnone
+
+define i32 @lshr_ctlz_zero_is_undef(i32 %x) {
+; CHECK-LABEL: @lshr_ctlz_zero_is_undef(
+; CHECK-NEXT:    ret i32 0
+;
+  %ct = call i32 @llvm.ctlz.i32(i32 %x, i1 true)
+  %sh = lshr i32 %ct, 5
+  ret i32 %sh
+}
+
+define i32 @lshr_cttz_zero_is_undef(i32 %x) {
+; CHECK-LABEL: @lshr_cttz_zero_is_undef(
+; CHECK-NEXT:    ret i32 0
+;
+  %ct = call i32 @llvm.cttz.i32(i32 %x, i1 true)
+  %sh = lshr i32 %ct, 5
+  ret i32 %sh
+}
+
+define <2 x i8> @lshr_ctlz_zero_is_undef_splat_vec(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_ctlz_zero_is_undef_splat_vec(
+; CHECK-NEXT:    ret <2 x i8> zeroinitializer
+;
+  %ct = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 true)
+  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
+  ret <2 x i8> %sh
+}
+
+define <2 x i8> @lshr_cttz_zero_is_undef_splat_vec(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_cttz_zero_is_undef_splat_vec(
+; CHECK-NEXT:    ret <2 x i8> zeroinitializer
+;
+  %ct = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 true)
+  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
+  ret <2 x i8> %sh
+}
+