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llvm-mirror/test/CodeGen/SystemZ/stackpointer.ll
Kai Nacke c31671a606 [SystemZ] Add implementation for the intrinsic llvm.read_register
This change implements the llvm intrinsic llvm.read_register for
the SystemZ platform which returns the value of the specified
register
(http://llvm.org/docs/LangRef.html#llvm-read-register-and-llvm-write-register-intrinsics).
This implementation returns the value of the stack register, and
can be extended to return the value of other registers. The
implementation for this intrinsic exists on various other platforms
including Power, x86, ARM, etc. but missing on SystemZ.

Reviewers: uweigand

Differential Revision: https://reviews.llvm.org/D73378
2020-02-10 08:19:10 -05:00

16 lines
352 B
LLVM

; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
define i8* @get_stack() nounwind {
entry:
; CHECK-LABEL: get_stack:
; CHECK: lgr %r2, %r15
; CHECK-NEXT: br %r14
%0 = call i64 @llvm.read_register.i64(metadata !0)
%1 = inttoptr i64 %0 to i8*
ret i8* %1
}
declare i64 @llvm.read_register.i64(metadata) nounwind
!0 = !{!"r15"}