llvm-6502/test/CodeGen/SystemZ/call-03.ll
Richard Sandiford 80f54784da [SystemZ] Add support for sibling calls
This first cut is pretty conservative.  The final argument register (R6)
is call-saved, so we would need to make sure that the R6 argument to a
sibling call is the same as the R6 argument to the calling function,
which seems worth keeping as a separate patch.

Saying that integer truncations are free means that we no longer
use the extending instructions LGF and LLGF for spills in int-conv-09.ll
and int-conv-10.ll.  Instead we treat the registers as 64 bits wide and
truncate them to 32-bits where necessary.  I think it's unlikely we'd
use LGF and LLGF for spills in other situations for the same reason,
so I'm removing the tests rather than replacing them.  The associated
code is generic and applies to many more instructions than just
LGF and LLGF, so there is no corresponding code removal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188669 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 12:42:31 +00:00

126 lines
3.4 KiB
LLVM

; Test sibling calls.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
declare void @ok(i8 %r2, i16 %r3, i32 %r4, i64 %r5, float %f0, double %f2,
float %f4, double %f6)
declare void @uses_r6(i8 %r2, i16 %r3, i32 %r4, i64 %r5, i64 %r6)
declare void @uses_indirect(fp128 %r2)
declare void @uses_stack(float %f0, float %f2, float %f4, float %f6,
float %stack)
declare i32 @returns_i32()
declare i64 @returns_i64()
; Check the maximum number of arguments that we can pass and still use
; a sibling call.
define void @f1() {
; CHECK-LABEL: f1:
; CHECK-DAG: lzer %f0
; CHECK-DAG: lzdr %f2
; CHECK-DAG: lhi %r2, 1
; CHECK-DAG: lhi %r3, 2
; CHECK-DAG: lhi %r4, 3
; CHECK-DAG: lghi %r5, 4
; CHECK-DAG: {{ler %f4, %f0|lzer %f4}}
; CHECK-DAG: {{ldr %f6, %f2|lzdr %f6}}
; CHECK: jg ok@PLT
tail call void @ok(i8 1, i16 2, i32 3, i64 4, float 0.0, double 0.0,
float 0.0, double 0.0)
ret void
}
; Check a call that uses %r6 to pass an argument. At the moment we don't
; use sibling calls in that case.
define void @f2() {
; CHECK-LABEL: f2:
; CHECK: brasl %r14, uses_r6@PLT
; CHECK: br %r14
tail call void @uses_r6(i8 1, i16 2, i32 3, i64 4, i64 5)
ret void
}
; Check a call that passes indirect arguments. We can't use sibling
; calls in that case.
define void @f3() {
; CHECK-LABEL: f3:
; CHECK: brasl %r14, uses_indirect@PLT
; CHECK: br %r14
tail call void @uses_indirect(fp128 0xL00000000000000000000000000000000)
ret void
}
; Check a call that uses direct stack arguments, which again prevents
; sibling calls
define void @f4() {
; CHECK-LABEL: f4:
; CHECK: brasl %r14, uses_stack@PLT
; CHECK: br %r14
tail call void @uses_stack(float 0.0, float 0.0, float 0.0, float 0.0,
float 0.0)
ret void
}
; Check an indirect call. In this case the only acceptable choice for
; the target register is %r1.
define void @f5(void(i32, i32, i32, i32) *%foo) {
; CHECK-LABEL: f5:
; CHECK: lgr %r1, %r2
; CHECK-DAG: lhi %r2, 1
; CHECK-DAG: lhi %r3, 2
; CHECK-DAG: lhi %r4, 3
; CHECK-DAG: lhi %r5, 4
; CHECK: br %r1
tail call void %foo(i32 1, i32 2, i32 3, i32 4)
ret void
}
; Check an indirect call that will be forced into a call-saved GPR
; (which should be %r13, the highest GPR not used for anything else).
define void @f6(void(i32) *%foo) {
; CHECK-LABEL: f6:
; CHECK: stmg %r13, %r15, 104(%r15)
; CHECK: lgr %r13, %r2
; CHECK: brasl %r14, returns_i32
; CHECK: lgr %r1, %r13
; CHECK: lmg %r13, %r15, 264(%r15)
; CHECK: br %r1
%arg = call i32 @returns_i32()
tail call void %foo(i32 %arg)
ret void
}
; Test a function that returns a value.
define i64 @f7() {
; CHECK-LABEL: f7:
; CHECK: jg returns_i64@PLT
%res = tail call i64 @returns_i64()
ret i64 %res
}
; Test a function that returns a value truncated from i64 to i32.
define i32 @f8() {
; CHECK-LABEL: f8:
; CHECK: jg returns_i64@PLT
%res = tail call i64 @returns_i64()
%trunc = trunc i64 %res to i32
ret i32 %trunc
}
; Test a function that returns a value truncated from i64 to i7.
define i7 @f9() {
; CHECK-LABEL: f9:
; CHECK: jg returns_i64@PLT
%res = tail call i64 @returns_i64()
%trunc = trunc i64 %res to i7
ret i7 %trunc
}
; Test a function that returns a value truncated from i32 to i8.
define i8 @f10() {
; CHECK-LABEL: f10:
; CHECK: jg returns_i32@PLT
%res = tail call i32 @returns_i32()
%trunc = trunc i32 %res to i8
ret i8 %trunc
}