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llvm-project/llvm/test/CodeGen/PowerPC/early-ret.ll

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Generate PPC early conditional returns PowerPC has a conditional branch to the link register (return) instruction: BCLR. This should be used any time when we'd otherwise have a conditional branch to a return. This adds a small pass, PPCEarlyReturn, which runs just prior to the branch selection pass (and, importantly, after block placement) to generate these conditional returns when possible. It will also eliminate unconditional branches to returns (these happen rarely; most of the time these have already been tail duplicated by the time PPCEarlyReturn is invoked). This is a nice optimization for small functions that do not maintain a stack frame. llvm-svn: 179026
2013-04-09 00:24:03 +08:00
; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 | FileCheck %s
target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
target triple = "powerpc64-unknown-linux-gnu"
define void @foo(i32* %P) #0 {
entry:
%tobool = icmp eq i32* %P, null
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
TBAA: remove !tbaa from testing cases if not used. This will make it easier to turn on struct-path aware TBAA since the metadata format will change. llvm-svn: 180796
2013-05-01 01:52:57 +08:00
store i32 0, i32* %P, align 4
Generate PPC early conditional returns PowerPC has a conditional branch to the link register (return) instruction: BCLR. This should be used any time when we'd otherwise have a conditional branch to a return. This adds a small pass, PPCEarlyReturn, which runs just prior to the branch selection pass (and, importantly, after block placement) to generate these conditional returns when possible. It will also eliminate unconditional branches to returns (these happen rarely; most of the time these have already been tail duplicated by the time PPCEarlyReturn is invoked). This is a nice optimization for small functions that do not maintain a stack frame. llvm-svn: 179026
2013-04-09 00:24:03 +08:00
br label %if.end
if.end: ; preds = %entry, %if.then
ret void
; CHECK: @foo
; CHECK: beqlr
; CHECK: blr
}
define void @bar(i32* %P, i32* %Q) #0 {
entry:
%tobool = icmp eq i32* %P, null
br i1 %tobool, label %if.else, label %if.then
if.then: ; preds = %entry
TBAA: remove !tbaa from testing cases if not used. This will make it easier to turn on struct-path aware TBAA since the metadata format will change. llvm-svn: 180796
2013-05-01 01:52:57 +08:00
store i32 0, i32* %P, align 4
Generate PPC early conditional returns PowerPC has a conditional branch to the link register (return) instruction: BCLR. This should be used any time when we'd otherwise have a conditional branch to a return. This adds a small pass, PPCEarlyReturn, which runs just prior to the branch selection pass (and, importantly, after block placement) to generate these conditional returns when possible. It will also eliminate unconditional branches to returns (these happen rarely; most of the time these have already been tail duplicated by the time PPCEarlyReturn is invoked). This is a nice optimization for small functions that do not maintain a stack frame. llvm-svn: 179026
2013-04-09 00:24:03 +08:00
%tobool1 = icmp eq i32* %Q, null
br i1 %tobool1, label %if.end3, label %if.then2
if.then2: ; preds = %if.then
TBAA: remove !tbaa from testing cases if not used. This will make it easier to turn on struct-path aware TBAA since the metadata format will change. llvm-svn: 180796
2013-05-01 01:52:57 +08:00
store i32 1, i32* %Q, align 4
Generate PPC early conditional returns PowerPC has a conditional branch to the link register (return) instruction: BCLR. This should be used any time when we'd otherwise have a conditional branch to a return. This adds a small pass, PPCEarlyReturn, which runs just prior to the branch selection pass (and, importantly, after block placement) to generate these conditional returns when possible. It will also eliminate unconditional branches to returns (these happen rarely; most of the time these have already been tail duplicated by the time PPCEarlyReturn is invoked). This is a nice optimization for small functions that do not maintain a stack frame. llvm-svn: 179026
2013-04-09 00:24:03 +08:00
br label %if.end3
if.else: ; preds = %entry
TBAA: remove !tbaa from testing cases if not used. This will make it easier to turn on struct-path aware TBAA since the metadata format will change. llvm-svn: 180796
2013-05-01 01:52:57 +08:00
store i32 0, i32* %Q, align 4
Generate PPC early conditional returns PowerPC has a conditional branch to the link register (return) instruction: BCLR. This should be used any time when we'd otherwise have a conditional branch to a return. This adds a small pass, PPCEarlyReturn, which runs just prior to the branch selection pass (and, importantly, after block placement) to generate these conditional returns when possible. It will also eliminate unconditional branches to returns (these happen rarely; most of the time these have already been tail duplicated by the time PPCEarlyReturn is invoked). This is a nice optimization for small functions that do not maintain a stack frame. llvm-svn: 179026
2013-04-09 00:24:03 +08:00
br label %if.end3
if.end3: ; preds = %if.then, %if.then2, %if.else
ret void
; CHECK: @bar
; CHECK: beqlr
; CHECK: blr
}
attributes #0 = { nounwind }