-; RUN: llc < %s -march=x86 -mcpu=yonah | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s
-define i32 @t1(i32 %x) nounwind {
- %tmp = tail call i32 @llvm.ctlz.i32( i32 %x, i1 true )
- ret i32 %tmp
-; CHECK: t1:
-; CHECK: bsrl
-; CHECK-NOT: cmov
-; CHECK: xorl $31,
-; CHECK: ret
+declare i8 @llvm.cttz.i8(i8, i1)
+declare i16 @llvm.cttz.i16(i16, i1)
+declare i32 @llvm.cttz.i32(i32, i1)
+declare i64 @llvm.cttz.i64(i64, i1)
+declare i8 @llvm.ctlz.i8(i8, i1)
+declare i16 @llvm.ctlz.i16(i16, i1)
+declare i32 @llvm.ctlz.i32(i32, i1)
+declare i64 @llvm.ctlz.i64(i64, i1)
+
+define i8 @cttz_i8(i8 %x) {
+; CHECK-LABEL: cttz_i8:
+; CHECK: # BB#0:
+; CHECK-NEXT: movzbl %dil, %eax
+; CHECK-NEXT: bsfl %eax, %eax
+; CHECK-NEXT: retq
+ %tmp = call i8 @llvm.cttz.i8( i8 %x, i1 true )
+ ret i8 %tmp
}
-declare i32 @llvm.ctlz.i32(i32, i1) nounwind readnone
+define i16 @cttz_i16(i16 %x) {
+; CHECK-LABEL: cttz_i16:
+; CHECK: # BB#0:
+; CHECK-NEXT: bsfw %di, %ax
+; CHECK-NEXT: retq
+ %tmp = call i16 @llvm.cttz.i16( i16 %x, i1 true )
+ ret i16 %tmp
+}
-define i32 @t2(i32 %x) nounwind {
- %tmp = tail call i32 @llvm.cttz.i32( i32 %x, i1 true )
+define i32 @cttz_i32(i32 %x) {
+; CHECK-LABEL: cttz_i32:
+; CHECK: # BB#0:
+; CHECK-NEXT: bsfl %edi, %eax
+; CHECK-NEXT: retq
+ %tmp = call i32 @llvm.cttz.i32( i32 %x, i1 true )
ret i32 %tmp
-; CHECK: t2:
-; CHECK: bsfl
-; CHECK-NOT: cmov
-; CHECK: ret
}
-declare i32 @llvm.cttz.i32(i32, i1) nounwind readnone
+define i64 @cttz_i64(i64 %x) {
+; CHECK-LABEL: cttz_i64:
+; CHECK: # BB#0:
+; CHECK-NEXT: bsfq %rdi, %rax
+; CHECK-NEXT: retq
+ %tmp = call i64 @llvm.cttz.i64( i64 %x, i1 true )
+ ret i64 %tmp
+}
+
+define i8 @ctlz_i8(i8 %x) {
+; CHECK-LABEL: ctlz_i8:
+; CHECK: # BB#0:
+; CHECK-NEXT: movzbl %dil, %eax
+; CHECK-NEXT: bsrl %eax, %eax
+; CHECK-NEXT: xorl $7, %eax
+; CHECK-NEXT: retq
+ %tmp2 = call i8 @llvm.ctlz.i8( i8 %x, i1 true )
+ ret i8 %tmp2
+}
-define i16 @t3(i16 %x, i16 %y) nounwind {
-entry:
- %tmp1 = add i16 %x, %y
- %tmp2 = tail call i16 @llvm.ctlz.i16( i16 %tmp1, i1 true ) ; <i16> [#uses=1]
+define i16 @ctlz_i16(i16 %x) {
+; CHECK-LABEL: ctlz_i16:
+; CHECK: # BB#0:
+; CHECK-NEXT: bsrw %di, %ax
+; CHECK-NEXT: xorl $15, %eax
+; CHECK-NEXT: retq
+ %tmp2 = call i16 @llvm.ctlz.i16( i16 %x, i1 true )
ret i16 %tmp2
-; CHECK: t3:
-; CHECK: bsrw
-; CHECK-NOT: cmov
-; CHECK: xorw $15,
-; CHECK: ret
}
-declare i16 @llvm.ctlz.i16(i16, i1) nounwind readnone
-
-define i32 @t4(i32 %n) nounwind {
-entry:
-; Generate a cmov to handle zero inputs when necessary.
-; CHECK: t4:
-; CHECK: bsrl
-; CHECK: cmov
-; CHECK: xorl $31,
-; CHECK: ret
- %tmp1 = tail call i32 @llvm.ctlz.i32(i32 %n, i1 false)
+define i32 @ctlz_i32(i32 %x) {
+; CHECK-LABEL: ctlz_i32:
+; CHECK: # BB#0:
+; CHECK-NEXT: bsrl %edi, %eax
+; CHECK-NEXT: xorl $31, %eax
+; CHECK-NEXT: retq
+ %tmp = call i32 @llvm.ctlz.i32( i32 %x, i1 true )
+ ret i32 %tmp
+}
+
+define i64 @ctlz_i64(i64 %x) {
+; CHECK-LABEL: ctlz_i64:
+; CHECK: # BB#0:
+; CHECK-NEXT: bsrq %rdi, %rax
+; CHECK-NEXT: xorq $63, %rax
+; CHECK-NEXT: retq
+ %tmp = call i64 @llvm.ctlz.i64( i64 %x, i1 true )
+ ret i64 %tmp
+}
+
+define i32 @ctlz_i32_zero_test(i32 %n) {
+; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
+
+; CHECK-LABEL: ctlz_i32_zero_test:
+; CHECK: # BB#0:
+; CHECK-NEXT: movl $32, %eax
+; CHECK-NEXT: testl %edi, %edi
+; CHECK-NEXT: je .LBB8_2
+; CHECK-NEXT: # BB#1: # %cond.false
+; CHECK-NEXT: bsrl %edi, %eax
+; CHECK-NEXT: xorl $31, %eax
+; CHECK-NEXT: .LBB8_2: # %cond.end
+; CHECK-NEXT: retq
+ %tmp1 = call i32 @llvm.ctlz.i32(i32 %n, i1 false)
ret i32 %tmp1
}
-define i32 @t5(i32 %n) nounwind {
-entry:
+define i32 @ctlz_i32_fold_cmov(i32 %n) {
; Don't generate the cmovne when the source is known non-zero (and bsr would
; not set ZF).
; rdar://9490949
-; CHECK: t5:
-; CHECK: bsrl
-; CHECK-NOT: cmov
-; CHECK: xorl $31,
-; CHECK: ret
+; FIXME: The compare and branch are produced late in IR (by CodeGenPrepare), and
+; codegen doesn't know how to delete the movl and je.
+
+; CHECK-LABEL: ctlz_i32_fold_cmov:
+; CHECK: # BB#0:
+; CHECK-NEXT: orl $1, %edi
+; CHECK-NEXT: movl $32, %eax
+; CHECK-NEXT: je .LBB9_2
+; CHECK-NEXT: # BB#1: # %cond.false
+; CHECK-NEXT: bsrl %edi, %eax
+; CHECK-NEXT: xorl $31, %eax
+; CHECK-NEXT: .LBB9_2: # %cond.end
+; CHECK-NEXT: retq
%or = or i32 %n, 1
- %tmp1 = tail call i32 @llvm.ctlz.i32(i32 %or, i1 false)
+ %tmp1 = call i32 @llvm.ctlz.i32(i32 %or, i1 false)
ret i32 %tmp1
}
+
+define i32 @ctlz_bsr(i32 %n) {
+; Don't generate any xors when a 'ctlz' intrinsic is actually used to compute
+; the most significant bit, which is what 'bsr' does natively.
+
+; CHECK-LABEL: ctlz_bsr:
+; CHECK: # BB#0:
+; CHECK-NEXT: bsrl %edi, %eax
+; CHECK-NEXT: retq
+ %ctlz = call i32 @llvm.ctlz.i32(i32 %n, i1 true)
+ %bsr = xor i32 %ctlz, 31
+ ret i32 %bsr
+}
+
+define i32 @ctlz_bsr_zero_test(i32 %n) {
+; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
+; FIXME: The compare and branch are produced late in IR (by CodeGenPrepare), and
+; codegen doesn't know how to combine the $32 and $31 into $63.
+
+; CHECK-LABEL: ctlz_bsr_zero_test:
+; CHECK: # BB#0:
+; CHECK-NEXT: movl $32, %eax
+; CHECK-NEXT: testl %edi, %edi
+; CHECK-NEXT: je .LBB11_2
+; CHECK-NEXT: # BB#1: # %cond.false
+; CHECK-NEXT: bsrl %edi, %eax
+; CHECK-NEXT: xorl $31, %eax
+; CHECK-NEXT: .LBB11_2: # %cond.end
+; CHECK-NEXT: xorl $31, %eax
+; CHECK-NEXT: retq
+ %ctlz = call i32 @llvm.ctlz.i32(i32 %n, i1 false)
+ %bsr = xor i32 %ctlz, 31
+ ret i32 %bsr
+}