[PowerPC] Add fast-isel branch and compare selection.

First chunk of actual fast-isel selection code.  This handles direct
and indirect branches, as well as feeding compares for direct
branches.  PPCFastISel::PPCEmitIntExt() is just roughed in and will be
expanded in a future patch.  This also corrects a problem with
selection for constant pool entries in JIT mode or with small code
model.

llvm-svn: 189202

2 files changed, 58 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/PowerPC/fast-isel-br-const.ll b/llvm/test/CodeGen/PowerPC/fast-isel-br-const.ll
new file mode 100644
index 00000000000..2cfb8a22574
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/fast-isel-br-const.ll
@@ -0,0 +1,43 @@
+; RUN: llc < %s -O0 -verify-machineinstrs -fast-isel-abort -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 | FileCheck %s --check-prefix=ELF64
+
+define i32 @t1(i32 %a, i32 %b) nounwind uwtable ssp {
+entry:
+; ELF64: t1
+  %x = add i32 %a, %b  
+  br i1 1, label %if.then, label %if.else
+; ELF64-NOT: b {{\.?}}LBB0_1
+
+if.then:                                          ; preds = %entry
+  call void @foo1()
+  br label %if.end7
+
+if.else:                                          ; preds = %entry
+  br i1 0, label %if.then2, label %if.else3
+; ELF64: b {{\.?}}LBB0_4
+
+if.then2:                                         ; preds = %if.else
+  call void @foo2()
+  br label %if.end6
+
+if.else3:                                         ; preds = %if.else
+  %y = sub i32 %a, %b
+  br i1 1, label %if.then5, label %if.end
+; ELF64-NOT: b {{\.?}}LBB0_5
+
+if.then5:                                         ; preds = %if.else3
+  call void @foo1()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then5, %if.else3
+  br label %if.end6
+
+if.end6:                                          ; preds = %if.end, %if.then2
+  br label %if.end7
+
+if.end7:                                          ; preds = %if.end6, %if.then
+  ret i32 0
+}
+
+declare void @foo1()
+
+declare void @foo2()
diff --git a/llvm/test/CodeGen/PowerPC/fast-isel-indirectbr.ll b/llvm/test/CodeGen/PowerPC/fast-isel-indirectbr.ll
new file mode 100644
index 00000000000..88ccf918ae9
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/fast-isel-indirectbr.ll
@@ -0,0 +1,15 @@
+; RUN: llc < %s -O0 -verify-machineinstrs -fast-isel-abort -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 | FileCheck %s --check-prefix=ELF64
+
+define void @t1(i8* %x) {
+entry:
+; ELF64: t1
+  br label %L0
+
+L0:
+  br label %L1
+
+L1:
+  indirectbr i8* %x, [ label %L0, label %L1 ]
+; ELF64: mtctr 3
+; ELF64: bctr
+}