llvm/test/CodeGen/SystemZ/strcmp-02.ll
Ulrich Weigand 05fbbee99e [SystemZ] Implement conditional returns
Return is now considered a predicable instruction, and is converted
to a newly-added CondReturn (which maps to BCR to %r14) instruction by
the if conversion pass.

Also, fused compare-and-branch transform knows about conditional
returns, emitting the proper fused instructions for them.

This transform triggers on a *lot* of tests, hence the huge diffstat.
The changes are mostly jX to br %r14 -> bXr %r14.

Author: koriakin

Differential Revision: http://reviews.llvm.org/D17339



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265689 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-07 16:11:44 +00:00

73 lines
1.7 KiB
LLVM

; Test strcmp using CLST, i64 version.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
declare i64 @strcmp(i8 *%src1, i8 *%src2)
; Check a case where the result is used as an integer.
define i64 @f1(i8 *%src1, i8 *%src2) {
; CHECK-LABEL: f1:
; CHECK: lhi %r0, 0
; CHECK: [[LABEL:\.[^:]*]]:
; CHECK: clst %r2, %r3
; CHECK-NEXT: jo [[LABEL]]
; CHECK-NEXT: BB#{{[0-9]+}}
; CHECK-NEXT: ipm [[REG:%r[0-5]]]
; CHECK: srl [[REG]], 28
; CHECK: rll [[REG]], [[REG]], 31
; CHECK: lgfr %r2, [[REG]]
; CHECK: br %r14
%res = call i64 @strcmp(i8 *%src1, i8 *%src2)
ret i64 %res
}
; Check a case where the result is tested for equality.
define void @f2(i8 *%src1, i8 *%src2, i64 *%dest) {
; CHECK-LABEL: f2:
; CHECK: lhi %r0, 0
; CHECK: [[LABEL:\.[^:]*]]:
; CHECK: clst %r2, %r3
; CHECK-NEXT: jo [[LABEL]]
; CHECK-NEXT: BB#{{[0-9]+}}
; CHECK-NEXT: ber %r14
; CHECK: br %r14
%res = call i64 @strcmp(i8 *%src1, i8 *%src2)
%cmp = icmp eq i64 %res, 0
br i1 %cmp, label %exit, label %store
store:
store i64 0, i64 *%dest
br label %exit
exit:
ret void
}
; Test a case where the result is used both as an integer and for
; branching.
define i64 @f3(i8 *%src1, i8 *%src2, i64 *%dest) {
; CHECK-LABEL: f3:
; CHECK: lhi %r0, 0
; CHECK: [[LABEL:\.[^:]*]]:
; CHECK: clst %r2, %r3
; CHECK-NEXT: jo [[LABEL]]
; CHECK-NEXT: BB#{{[0-9]+}}
; CHECK-NEXT: ipm [[REG:%r[0-5]]]
; CHECK: srl [[REG]], 28
; CHECK: rll [[REG]], [[REG]], 31
; CHECK: lgfr %r2, [[REG]]
; CHECK: blr %r14
; CHECK: br %r14
entry:
%res = call i64 @strcmp(i8 *%src1, i8 *%src2)
%cmp = icmp slt i64 %res, 0
br i1 %cmp, label %exit, label %store
store:
store i64 0, i64 *%dest
br label %exit
exit:
ret i64 %res
}