[SystemZ] Support conditional sibling calls via BRCL

This adds a conditional variant of CallJG instruction, CallBRCL.
It can be used for conditional sibling calls. Unfortunately, due
to IfCvt limitations, it only really works well for functions without
arguments.

Author: koriakin
Differential Revision: http://reviews.llvm.org/D18864

llvm-svn: 265814

1 files changed, 369 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/SystemZ/call-04.ll b/llvm/test/CodeGen/SystemZ/call-04.ll
new file mode 100644
index 00000000000..12e0d596676
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/call-04.ll
@@ -0,0 +1,369 @@
+; Test conditional sibling calls.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare void @fun_a()
+declare void @fun_b()
+declare void @fun_c(i32)
+
+@var = global i32 1;
+
+; Check a conditional sibling call.
+define void @f1(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f1:
+; CHECK: cr %r2, %r3
+; CHECK: jgl fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp slt i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call when there are two possibilities.
+define void @f2(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f2:
+; CHECK: cr %r2, %r3
+; CHECK: jghe fun_b@PLT
+; CHECK: jg fun_a@PLT
+  %cond = icmp slt i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  tail call void @fun_b()
+  ret void
+}
+
+; Check a conditional sibling call with an argument - not supported.
+define void @f3(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f3:
+; CHECK: crjhe %r2, %r3
+; CHECK: jg fun_c@PLT
+; CHECK: br %r14
+  %cond = icmp slt i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_c(i32 1)
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - unsigned compare.
+define void @f4(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f4:
+; CHECK: clr %r2, %r3
+; CHECK: jgl fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp ult i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - 64-bit compare.
+define void @f5(i64 %val1, i64 %val2) {
+; CHECK-LABEL: f5:
+; CHECK: cgr %r2, %r3
+; CHECK: jgl fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp slt i64 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - unsigned 64-bit compare.
+define void @f6(i64 %val1, i64 %val2) {
+; CHECK-LABEL: f6:
+; CHECK: clgr %r2, %r3
+; CHECK: jgl fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp ult i64 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - less-equal compare.
+define void @f7(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f7:
+; CHECK: cr %r2, %r3
+; CHECK: jgle fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp sle i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - high compare.
+define void @f8(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f8:
+; CHECK: cr %r2, %r3
+; CHECK: jgh fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp sgt i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - high-equal compare.
+define void @f9(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f9:
+; CHECK: cr %r2, %r3
+; CHECK: jghe fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp sge i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - equal compare.
+define void @f10(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f10:
+; CHECK: cr %r2, %r3
+; CHECK: jge fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp eq i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - unequal compare.
+define void @f11(i32 %val1, i32 %val2) {
+; CHECK-LABEL: f11:
+; CHECK: cr %r2, %r3
+; CHECK: jglh fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp ne i32 %val1, %val2;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate slt.
+define void @f12(i32 %val1) {
+; CHECK-LABEL: f12:
+; CHECK: chi %r2, 4
+; CHECK: jgle fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp slt i32 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate sle.
+define void @f13(i32 %val1) {
+; CHECK-LABEL: f13:
+; CHECK: chi %r2, 5
+; CHECK: jgle fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp sle i32 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate sgt.
+define void @f14(i32 %val1) {
+; CHECK-LABEL: f14:
+; CHECK: chi %r2, 6
+; CHECK: jghe fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp sgt i32 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate sge.
+define void @f15(i32 %val1) {
+; CHECK-LABEL: f15:
+; CHECK: chi %r2, 5
+; CHECK: jghe fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp sge i32 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate eq.
+define void @f16(i32 %val1) {
+; CHECK-LABEL: f16:
+; CHECK: chi %r2, 5
+; CHECK: jge fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp eq i32 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate ne.
+define void @f17(i32 %val1) {
+; CHECK-LABEL: f17:
+; CHECK: chi %r2, 5
+; CHECK: jglh fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp ne i32 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate ult.
+define void @f18(i32 %val1) {
+; CHECK-LABEL: f18:
+; CHECK: clfi %r2, 4
+; CHECK: jgle fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp ult i32 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate 64-bit slt.
+define void @f19(i64 %val1) {
+; CHECK-LABEL: f19:
+; CHECK: cghi %r2, 4
+; CHECK: jgle fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp slt i64 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}
+
+; Check a conditional sibling call - immediate 64-bit ult.
+define void @f20(i64 %val1) {
+; CHECK-LABEL: f20:
+; CHECK: clgfi %r2, 4
+; CHECK: jgle fun_a@PLT
+; CHECK: br %r14
+  %cond = icmp ult i64 %val1, 5;
+  br i1 %cond, label %a, label %b;
+
+a:
+  tail call void @fun_a()
+  ret void
+
+b:
+  store i32 1, i32 *@var;
+  ret void
+}