1 files changed, 134 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/ffs-1.ll b/test/Transforms/InstCombine/ffs-1.ll
new file mode 100644
index 0000000..0510df3
--- /dev/null
+++ b/test/Transforms/InstCombine/ffs-1.ll
@@ -0,0 +1,134 @@
+; Test that the ffs* library call simplifier works correctly.
+;
+; RUN: opt < %s -instcombine -S | FileCheck %s
+; RUN: opt < %s -mtriple i386-pc-linux -instcombine -S | FileCheck %s -check-prefix=LINUX
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+
+declare i32 @ffs(i32)
+declare i32 @ffsl(i32)
+declare i32 @ffsll(i64)
+
+; Check ffs(0) -> 0.
+
+define i32 @test_simplify1() {
+; CHECK: @test_simplify1
+  %ret = call i32 @ffs(i32 0)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 0
+}
+
+define i32 @test_simplify2() {
+; CHECK-LINUX: @test_simplify2
+  %ret = call i32 @ffsl(i32 0)
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 0
+}
+
+define i32 @test_simplify3() {
+; CHECK-LINUX: @test_simplify3
+  %ret = call i32 @ffsll(i64 0)
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 0
+}
+
+; Check ffs(c) -> cttz(c) + 1, where 'c' is a constant.
+
+define i32 @test_simplify4() {
+; CHECK: @test_simplify4
+  %ret = call i32 @ffs(i32 1)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 1
+}
+
+define i32 @test_simplify5() {
+; CHECK: @test_simplify5
+  %ret = call i32 @ffs(i32 2048)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 12
+}
+
+define i32 @test_simplify6() {
+; CHECK: @test_simplify6
+  %ret = call i32 @ffs(i32 65536)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 17
+}
+
+define i32 @test_simplify7() {
+; CHECK-LINUX: @test_simplify7
+  %ret = call i32 @ffsl(i32 65536)
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 17
+}
+
+define i32 @test_simplify8() {
+; CHECK-LINUX: @test_simplify8
+  %ret = call i32 @ffsll(i64 1024)
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 11
+}
+
+define i32 @test_simplify9() {
+; CHECK-LINUX: @test_simplify9
+  %ret = call i32 @ffsll(i64 65536)
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 17
+}
+
+define i32 @test_simplify10() {
+; CHECK-LINUX: @test_simplify10
+  %ret = call i32 @ffsll(i64 17179869184)
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 35
+}
+
+define i32 @test_simplify11() {
+; CHECK-LINUX: @test_simplify11
+  %ret = call i32 @ffsll(i64 281474976710656)
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 49
+}
+
+define i32 @test_simplify12() {
+; CHECK-LINUX: @test_simplify12
+  %ret = call i32 @ffsll(i64 1152921504606846976)
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 61
+}
+
+; Check ffs(x) -> x != 0 ? (i32)llvm.cttz(x) + 1 : 0.
+
+define i32 @test_simplify13(i32 %x) {
+; CHECK: @test_simplify13
+  %ret = call i32 @ffs(i32 %x)
+; CHECK-NEXT: [[CTTZ:%[a-z0-9]+]] = call i32 @llvm.cttz.i32(i32 %x, i1 false)
+; CHECK-NEXT: [[INC:%[a-z0-9]+]] = add i32 [[CTTZ]], 1
+; CHECK-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i32 %x, 0
+; CHECK-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[INC]], i32 0
+  ret i32 %ret
+; CHECK-NEXT: ret i32 [[RET]]
+}
+
+define i32 @test_simplify14(i32 %x) {
+; CHECK-LINUX: @test_simplify14
+  %ret = call i32 @ffsl(i32 %x)
+; CHECK-LINUX-NEXT: [[CTTZ:%[a-z0-9]+]] = call i32 @llvm.cttz.i32(i32 %x, i1 false)
+; CHECK-LINUX-NEXT: [[INC:%[a-z0-9]+]] = add i32 [[CTTZ]], 1
+; CHECK-LINUX-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i32 %x, 0
+; CHECK-LINUX-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[INC]], i32 0
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 [[RET]]
+}
+
+define i32 @test_simplify15(i64 %x) {
+; CHECK-LINUX: @test_simplify15
+  %ret = call i32 @ffsll(i64 %x)
+; CHECK-LINUX-NEXT: [[CTTZ:%[a-z0-9]+]] = call i64 @llvm.cttz.i64(i64 %x, i1 false)
+; CHECK-LINUX-NEXT: [[INC:%[a-z0-9]+]] = add i64 [[CTTZ]], 1
+; CHECK-LINUX-NEXT: [[TRUNC:%[a-z0-9]+]] = trunc i64 [[INC]] to i32
+; CHECK-LINUX-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i64 %x, 0
+; CHECK-LINUX-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[TRUNC]], i32 0
+  ret i32 %ret
+; CHECK-LINUX-NEXT: ret i32 [[RET]]
+}