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llvm-project/llvm/test/CodeGen/X86/musttail.ll

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X86: Do not use llc -march in tests. `llc -march` is problematic because it only switches the target architecture, but leaves the operating system unchanged. This occasionally leads to indeterministic tests because the OS from LLVM_DEFAULT_TARGET_TRIPLE is used. However we can simply always use `llc -mtriple` instead. This changes all the tests to do this to avoid people using -march when they copy and paste parts of tests. See also the discussion in https://reviews.llvm.org/D35287 llvm-svn: 309774
2017-08-02 08:28:10 +08:00
; RUN: llc -mtriple=i686-- < %s | FileCheck %s
; RUN: llc -mtriple=i686-- -O0 < %s | FileCheck %s
; RUN: llc -mtriple=i686-- -disable-tail-calls < %s | FileCheck %s
Add 'musttail' marker to call instructions This is similar to the 'tail' marker, except that it guarantees that tail call optimization will occur. It also comes with convervative IR verification rules that ensure that tail call optimization is possible. Reviewers: nicholas Differential Revision: http://llvm-reviews.chandlerc.com/D3240 llvm-svn: 207143
2014-04-25 04:14:34 +08:00
declare void @t1_callee(i8*)
define void @t1(i32* %a) {
; CHECK-LABEL: t1:
; CHECK: jmp {{_?}}t1_callee
%b = bitcast i32* %a to i8*
musttail call void @t1_callee(i8* %b)
ret void
}
declare i8* @t2_callee()
define i32* @t2() {
; CHECK-LABEL: t2:
; CHECK: jmp {{_?}}t2_callee
%v = musttail call i8* @t2_callee()
%w = bitcast i8* %v to i32*
ret i32* %w
}
Implement X86 code generation for musttail Currently, musttail codegen is relying on sibcall optimization, and reporting a fatal error if fails. Sibcall optimization fails when stack arguments need to be modified, which is insufficient for musttail. The logic for moving arguments in memory safely is already implemented for GuaranteedTailCallOpt. This change merely arranges for musttail calls to use it. No functional change for GuaranteedTailCallOpt. Reviewers: espindola Differential Revision: http://reviews.llvm.org/D3493 llvm-svn: 207598
2014-04-30 07:55:41 +08:00
; Complex frame layout: stack realignment with dynamic alloca.
define void @t3(i32 %n) alignstack(32) nounwind {
entry:
; CHECK: t3:
; CHECK: pushl %ebp
; CHECK: pushl %esi
; CHECK: andl $-32, %esp
; CHECK: movl %esp, %esi
; CHECK: popl %esi
; CHECK: popl %ebp
; CHECK-NEXT: jmp {{_?}}t3_callee
%a = alloca i8, i32 %n
call void @capture(i8* %a)
musttail call void @t3_callee(i32 %n) nounwind
ret void
}
declare void @capture(i8*)
declare void @t3_callee(i32)
; Test that we actually copy in and out stack arguments that aren't forwarded
; without modification.
define i32 @t4({}* %fn, i32 %n, i32 %r) {
; CHECK-LABEL: t4:
; CHECK: incl %[[r:.*]]
; CHECK: decl %[[n:.*]]
; CHECK: movl %[[r]], {{[0-9]+}}(%esp)
; CHECK: movl %[[n]], {{[0-9]+}}(%esp)
; CHECK: jmpl *%{{.*}}
entry:
%r1 = add i32 %r, 1
%n1 = sub i32 %n, 1
%fn_cast = bitcast {}* %fn to i32 ({}*, i32, i32)*
%r2 = musttail call i32 %fn_cast({}* %fn, i32 %n1, i32 %r1)
ret i32 %r2
}
; Combine the complex stack frame with the parameter modification.
define i32 @t5({}* %fn, i32 %n, i32 %r) alignstack(32) {
; CHECK-LABEL: t5:
; CHECK: pushl %ebp
; CHECK: movl %esp, %ebp
; CHECK: pushl %esi
; Align the stack.
; CHECK: andl $-32, %esp
; CHECK: movl %esp, %esi
; Modify the args.
; CHECK: incl %[[r:.*]]
; CHECK: decl %[[n:.*]]
; Store them through ebp, since that's the only stable arg pointer.
; CHECK: movl %[[r]], {{[0-9]+}}(%ebp)
; CHECK: movl %[[n]], {{[0-9]+}}(%ebp)
; Epilogue.
; CHECK: leal {{[-0-9]+}}(%ebp), %esp
; CHECK: popl %esi
; CHECK: popl %ebp
; CHECK: jmpl *%{{.*}}
entry:
%a = alloca i8, i32 %n
call void @capture(i8* %a)
%r1 = add i32 %r, 1
%n1 = sub i32 %n, 1
%fn_cast = bitcast {}* %fn to i32 ({}*, i32, i32)*
%r2 = musttail call i32 %fn_cast({}* %fn, i32 %n1, i32 %r1)
ret i32 %r2
}