llvm/test/CodeGen/X86/or-branch.ll
Sanjay Patel 9f33e3748e use "unpredictable" metadata in SelectionDAG when splitting compares
This patch uses the metadata defined in D12341 to avoid creating an unpredictable branch.

Differential Revision: http://reviews.llvm.org/D12343



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246691 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 19:17:25 +00:00

55 lines
1.3 KiB
LLVM

; RUN: llc < %s -mtriple=i386-unknown-unknown -jump-is-expensive=0 | FileCheck %s --check-prefix=JUMP2 --check-prefix=CHECK
; RUN: llc < %s -mtriple=i386-unknown-unknown -jump-is-expensive=1 | FileCheck %s --check-prefix=JUMP1 --check-prefix=CHECK
define void @foo(i32 %X, i32 %Y, i32 %Z) nounwind {
; JUMP2-LABEL: foo:
; JUMP2-DAG: jl
; JUMP2-DAG: je
;
; JUMP1-LABEL: foo:
; JUMP1-DAG: sete
; JUMP1-DAG: setl
; JUMP1: orb
; JUMP1: jne
entry:
%tmp1 = icmp eq i32 %X, 0
%tmp3 = icmp slt i32 %Y, 5
%tmp4 = or i1 %tmp3, %tmp1
br i1 %tmp4, label %cond_true, label %UnifiedReturnBlock
cond_true:
%tmp5 = tail call i32 (...) @bar( )
ret void
UnifiedReturnBlock:
ret void
}
; If the branch is unpredictable, don't add another branch
; regardless of whether they are expensive or not.
define void @unpredictable(i32 %X, i32 %Y, i32 %Z) nounwind {
; CHECK-LABEL: unpredictable:
; CHECK-DAG: sete
; CHECK-DAG: setl
; CHECK: orb
; CHECK: jne
entry:
%tmp1 = icmp eq i32 %X, 0
%tmp3 = icmp slt i32 %Y, 5
%tmp4 = or i1 %tmp3, %tmp1
br i1 %tmp4, label %cond_true, label %UnifiedReturnBlock, !unpredictable !0
cond_true:
%tmp5 = tail call i32 (...) @bar( )
ret void
UnifiedReturnBlock:
ret void
}
declare i32 @bar(...)
!0 = !{}