1 files changed, 193 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/ffs-1.ll b/llvm/test/Transforms/InstCombine/ffs-1.ll
new file mode 100644
index 00000000000..5be47efb178
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/ffs-1.ll
@@ -0,0 +1,193 @@
+; Test that the ffs* library call simplifier works correctly.
+;
+; RUN: opt < %s -instcombine -S                                    | FileCheck %s --check-prefix=ALL --check-prefix=GENERIC
+; RUN: opt < %s -instcombine -mtriple i386-pc-linux -S             | FileCheck %s --check-prefix=ALL --check-prefix=TARGET
+; RUN: opt < %s -instcombine -mtriple=arm64-apple-ios9.0 -S        | FileCheck %s --check-prefix=ALL --check-prefix=TARGET
+; RUN: opt < %s -instcombine -mtriple=arm64-apple-tvos9.0 -S       | FileCheck %s --check-prefix=ALL --check-prefix=TARGET
+; RUN: opt < %s -instcombine -mtriple=thumbv7k-apple-watchos2.0 -S | FileCheck %s --check-prefix=ALL --check-prefix=TARGET
+; RUN: opt < %s -instcombine -mtriple=x86_64-apple-macosx10.11 -S  | FileCheck %s --check-prefix=ALL --check-prefix=TARGET
+; RUN: opt < %s -instcombine -mtriple=x86_64-freebsd-gnu -S        | FileCheck %s --check-prefix=ALL --check-prefix=TARGET
+
+declare i32 @ffs(i32)
+declare i32 @ffsl(i32)
+declare i32 @ffsll(i64)
+
+; Check ffs(0) -> 0.
+
+define i32 @test_simplify1() {
+; ALL-LABEL: @test_simplify1(
+; ALL-NEXT:    ret i32 0
+;
+  %ret = call i32 @ffs(i32 0)
+  ret i32 %ret
+}
+
+define i32 @test_simplify2() {
+; GENERIC-LABEL: @test_simplify2(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsl(i32 0)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify2(
+; TARGET-NEXT:    ret i32 0
+;
+  %ret = call i32 @ffsl(i32 0)
+  ret i32 %ret
+}
+
+define i32 @test_simplify3() {
+; GENERIC-LABEL: @test_simplify3(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsll(i64 0)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify3(
+; TARGET-NEXT:    ret i32 0
+;
+  %ret = call i32 @ffsll(i64 0)
+  ret i32 %ret
+}
+
+; Check ffs(c) -> cttz(c) + 1, where 'c' is a constant.
+
+define i32 @test_simplify4() {
+; ALL-LABEL: @test_simplify4(
+; ALL-NEXT:    ret i32 1
+;
+  %ret = call i32 @ffs(i32 1)
+  ret i32 %ret
+}
+
+define i32 @test_simplify5() {
+; ALL-LABEL: @test_simplify5(
+; ALL-NEXT:    ret i32 12
+;
+  %ret = call i32 @ffs(i32 2048)
+  ret i32 %ret
+}
+
+define i32 @test_simplify6() {
+; ALL-LABEL: @test_simplify6(
+; ALL-NEXT:    ret i32 17
+;
+  %ret = call i32 @ffs(i32 65536)
+  ret i32 %ret
+}
+
+define i32 @test_simplify7() {
+; GENERIC-LABEL: @test_simplify7(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsl(i32 65536)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify7(
+; TARGET-NEXT:    ret i32 17
+;
+  %ret = call i32 @ffsl(i32 65536)
+  ret i32 %ret
+}
+
+define i32 @test_simplify8() {
+; GENERIC-LABEL: @test_simplify8(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsll(i64 1024)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify8(
+; TARGET-NEXT:    ret i32 11
+;
+  %ret = call i32 @ffsll(i64 1024)
+  ret i32 %ret
+}
+
+define i32 @test_simplify9() {
+; GENERIC-LABEL: @test_simplify9(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsll(i64 65536)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify9(
+; TARGET-NEXT:    ret i32 17
+;
+  %ret = call i32 @ffsll(i64 65536)
+  ret i32 %ret
+}
+
+define i32 @test_simplify10() {
+; GENERIC-LABEL: @test_simplify10(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsll(i64 17179869184)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify10(
+; TARGET-NEXT:    ret i32 35
+;
+  %ret = call i32 @ffsll(i64 17179869184)
+  ret i32 %ret
+}
+
+define i32 @test_simplify11() {
+; GENERIC-LABEL: @test_simplify11(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsll(i64 281474976710656)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify11(
+; TARGET-NEXT:    ret i32 49
+;
+  %ret = call i32 @ffsll(i64 281474976710656)
+  ret i32 %ret
+}
+
+define i32 @test_simplify12() {
+; GENERIC-LABEL: @test_simplify12(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsll(i64 1152921504606846976)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify12(
+; TARGET-NEXT:    ret i32 61
+;
+  %ret = call i32 @ffsll(i64 1152921504606846976)
+  ret i32 %ret
+}
+
+; Check ffs(x) -> x != 0 ? (i32)llvm.cttz(x) + 1 : 0.
+
+define i32 @test_simplify13(i32 %x) {
+; ALL-LABEL: @test_simplify13(
+; ALL-NEXT:    [[CTTZ:%.*]] = call i32 @llvm.cttz.i32(i32 %x, i1 true), !range !0
+; ALL-NEXT:    [[TMP1:%.*]] = add nuw nsw i32 [[CTTZ]], 1
+; ALL-NEXT:    [[TMP2:%.*]] = icmp eq i32 %x, 0
+; ALL-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 0, i32 [[TMP1]]
+; ALL-NEXT:    ret i32 [[TMP3]]
+;
+  %ret = call i32 @ffs(i32 %x)
+  ret i32 %ret
+}
+
+define i32 @test_simplify14(i32 %x) {
+; GENERIC-LABEL: @test_simplify14(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsl(i32 %x)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify14(
+; TARGET-NEXT:    [[CTTZ:%.*]] = call i32 @llvm.cttz.i32(i32 %x, i1 true), !range !0
+; TARGET-NEXT:    [[TMP1:%.*]] = add nuw nsw i32 [[CTTZ]], 1
+; TARGET-NEXT:    [[TMP2:%.*]] = icmp eq i32 %x, 0
+; TARGET-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 0, i32 [[TMP1]]
+; TARGET-NEXT:    ret i32 [[TMP3]]
+;
+  %ret = call i32 @ffsl(i32 %x)
+  ret i32 %ret
+}
+
+define i32 @test_simplify15(i64 %x) {
+; GENERIC-LABEL: @test_simplify15(
+; GENERIC-NEXT:    [[RET:%.*]] = call i32 @ffsll(i64 %x)
+; GENERIC-NEXT:    ret i32 [[RET]]
+;
+; TARGET-LABEL: @test_simplify15(
+; TARGET-NEXT:    [[CTTZ:%.*]] = call i64 @llvm.cttz.i64(i64 %x, i1 true), !range !1
+; TARGET-NEXT:    [[TMP1:%.*]] = trunc i64 [[CTTZ]] to i32
+; TARGET-NEXT:    [[TMP2:%.*]] = add nuw nsw i32 [[TMP1]], 1
+; TARGET-NEXT:    [[TMP3:%.*]] = icmp eq i64 %x, 0
+; TARGET-NEXT:    [[TMP4:%.*]] = select i1 [[TMP3]], i32 0, i32 [[TMP2]]
+; TARGET-NEXT:    ret i32 [[TMP4]]
+;
+  %ret = call i32 @ffsll(i64 %x)
+  ret i32 %ret
+}
+