You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
113 lines
3.6 KiB
113 lines
3.6 KiB
4 months ago
|
; RUN: llc -mtriple armv7 -target-abi apcs -O0 -o - < %s \
|
||
|
|
; RUN: | FileCheck %s -check-prefix CHECK-TAIL -check-prefix CHECK
|
||
|
|
; RUN: llc -mtriple armv7 -target-abi apcs -O0 -disable-tail-calls -o - < %s \
|
||
|
|
; RUN: | FileCheck %s -check-prefix CHECK-NO-TAIL -check-prefix CHECK
|
||
|
|
; RUN: llc -mtriple armv7 -target-abi aapcs -O0 -o - < %s \
|
||
|
|
; RUN: | FileCheck %s -check-prefix CHECK-TAIL-AAPCS -check-prefix CHECK
|
||
|
|
|
||
|
|
declare i32 @callee(i32 %i)
|
||
|
|
declare extern_weak fastcc void @callee_weak()
|
||
|
|
|
||
|
|
define i32 @caller(i32 %i) {
|
||
|
|
entry:
|
||
|
|
%r = tail call i32 @callee(i32 %i)
|
||
|
|
ret i32 %r
|
||
|
|
}
|
||
|
|
|
||
|
|
; CHECK-TAIL-LABEL: caller
|
||
|
|
; CHECK-TAIL: b callee
|
||
|
|
|
||
|
|
; CHECK-NO-TAIL-LABEL: caller
|
||
|
|
; CHECK-NO-TAIL: push {lr}
|
||
|
|
; CHECK-NO-TAIL: bl callee
|
||
|
|
; CHECK-NO-TAIL: pop {lr}
|
||
|
|
; CHECK-NO-TAIL: bx lr
|
||
|
|
|
||
|
|
|
||
|
|
; Weakly-referenced extern functions cannot be tail-called, as AAELF does
|
||
|
|
; not define the behaviour of branch instructions to undefined weak symbols.
|
||
|
|
define fastcc void @caller_weak() {
|
||
|
|
; CHECK-LABEL: caller_weak:
|
||
|
|
; CHECK: bl callee_weak
|
||
|
|
tail call void @callee_weak()
|
||
|
|
ret void
|
||
|
|
}
|
||
|
|
|
||
|
|
; A tail call can be optimized if all the arguments can be passed in registers
|
||
|
|
; R0-R3, or the remaining arguments are already in the caller's parameter area
|
||
|
|
; in the stack. Variadic functions are no different.
|
||
|
|
declare i32 @variadic(i32, ...)
|
||
|
|
|
||
|
|
; e.g. four integers
|
||
|
|
define void @v_caller_ints1(i32 %a, i32 %b) {
|
||
|
|
; CHECK-LABEL: v_caller_ints1:
|
||
|
|
; CHECK-TAIL: b variadic
|
||
|
|
; CHECK-TAIL-AAPCS: b variadic
|
||
|
|
; CHECK-NO-TAIL: bl variadic
|
||
|
|
entry:
|
||
|
|
%call = tail call i32 (i32, ...) @variadic(i32 %a, i32 %b, i32 %b, i32 %a)
|
||
|
|
ret void
|
||
|
|
}
|
||
|
|
|
||
|
|
; e.g. two 32-bit integers, one 64-bit integer (needs to span two regs)
|
||
|
|
define void @v_caller_ints2(i32 %y, i64 %z) {
|
||
|
|
; CHECK-LABEL: v_caller_ints2:
|
||
|
|
; CHECK-TAIL: b variadic
|
||
|
|
; CHECK-TAIL-AAPCS: b variadic
|
||
|
|
; CHECK-NO-TAIL: bl variadic
|
||
|
|
entry:
|
||
|
|
%call = tail call i32 (i32, ...) @variadic(i32 %y, i32 %y, i64 %z)
|
||
|
|
ret void
|
||
|
|
}
|
||
|
|
|
||
|
|
; e.g. two 32-bit integers, one 64-bit integer (needs to span two regs). Notice
|
||
|
|
; that %z is passed in r1-r2 if APCS is used, contrary to AAPCS where r2-r3
|
||
|
|
; would be used (since double-word types must start at an even register). In the
|
||
|
|
; latter case, the third argument needs to be passed through the stack.
|
||
|
|
define void @v_caller_ints3(i32 %y, i64 %z) {
|
||
|
|
; CHECK-LABEL: v_caller_ints3:
|
||
|
|
; CHECK-TAIL: b variadic
|
||
|
|
; CHECK-TAIL-AAPCS: bl variadic
|
||
|
|
; CHECK-NO-TAIL: bl variadic
|
||
|
|
entry:
|
||
|
|
%call = tail call i32 (i32, ...) @variadic(i32 %y, i64 %z, i32 %y)
|
||
|
|
ret void
|
||
|
|
}
|
||
|
|
|
||
|
|
; e.g. two 32-bit integers, one 64-bit integer and another 64-bit integer that
|
||
|
|
; doesn't fit in r0-r3 but comes from the caller argument list and is in the
|
||
|
|
; same position.
|
||
|
|
define void @v_caller_ints4(i64 %a, i32 %b, i32 %c, i64 %d) {
|
||
|
|
; CHECK-LABEL: v_caller_ints4:
|
||
|
|
; CHECK-TAIL: b variadic
|
||
|
|
; CHECK-TAIL-AAPCS: b variadic
|
||
|
|
; CHECK-NO-TAIL: bl variadic
|
||
|
|
entry:
|
||
|
|
%call = tail call i32 (i32, ...) @variadic(i32 %b, i32 %c, i64 %a, i64 %d)
|
||
|
|
ret void
|
||
|
|
}
|
||
|
|
|
||
|
|
; If the arguments do not fit in r0-r3 and the existing parameters cannot be
|
||
|
|
; taken from the caller's parameter region, the optimization is not supported.
|
||
|
|
|
||
|
|
; e.g. one 32-bit integer, two 64-bit integers
|
||
|
|
define void @v_caller_ints_fail(i32 %y, i64 %z) {
|
||
|
|
; CHECK-LABEL: v_caller_ints_fail:
|
||
|
|
; CHECK: bl variadic
|
||
|
|
entry:
|
||
|
|
%call = tail call i32 (i32, ...) @variadic(i32 %y, i64 %z, i64 %z)
|
||
|
|
ret void
|
||
|
|
}
|
||
|
|
|
||
|
|
; Check that NonNull attributes don't inhibit tailcalls.
|
||
|
|
|
||
|
|
declare nonnull i8* @nonnull_callee(i8* %p, i32 %val)
|
||
|
|
define i8* @nonnull_caller(i8* %p, i32 %val) {
|
||
|
|
; CHECK-LABEL: nonnull_caller:
|
||
|
|
; CHECK-TAIL: b nonnull_callee
|
||
|
|
; CHECK-NO-TAIL: bl nonnull_callee
|
||
|
|
entry:
|
||
|
|
%call = tail call i8* @nonnull_callee(i8* %p, i32 %val)
|
||
|
|
ret i8* %call
|
||
|
|
}
|