[llvm-extract] Support extracting basic blocks

Summary:
Currently, there is no way to extract a basic block from a function easily. This patch
extends llvm-extract to extract the specified basic block(s).

Reviewers: loladiro, rafael, bogner

Reviewed By: bogner

Subscribers: hintonda, mgorny, qcolombet, llvm-commits

Differential Revision: https://reviews.llvm.org/D41638

llvm-svn: 323266

3 files changed, 61 insertions, 0 deletions

diff --git a/llvm/test/Transforms/BlockExtractor/extract-blocks.ll b/llvm/test/Transforms/BlockExtractor/extract-blocks.ll
new file mode 100644
index 00000000000..daf9a0923ce
--- /dev/null
+++ b/llvm/test/Transforms/BlockExtractor/extract-blocks.ll
@@ -0,0 +1,43 @@
+; RUN: echo 'foo bb9' > %t
+; RUN: echo 'foo bb20' >> %t
+; RUN: opt -S -extract-blocks -extract-blocks-file=%t %s | FileCheck %s --check-prefix=CHECK-NO-ERASE
+; RUN: opt -S -extract-blocks -extract-blocks-file=%t -extract-blocks-erase-funcs %s | FileCheck %s --check-prefix=CHECK-ERASE
+
+; CHECK-NO-ERASE: @foo(
+; CHECK-NO-ERASE: @foo_bb9(
+; CHECK-NO-ERASE: @foo_bb20(
+; CHECK-ERASE-NOT: @foo(
+; CHECK-ERASE: @foo_bb9(
+; CHECK-ERASE: @foo_bb20(
+define i32 @foo(i32 %arg, i32 %arg1) {
+bb:
+  %tmp5 = icmp sgt i32 %arg, 0
+  %tmp8 = icmp sgt i32 %arg1, 0
+  %or.cond = and i1 %tmp5, %tmp8
+  br i1 %or.cond, label %bb9, label %bb14
+
+bb9:                                              ; preds = %bb
+  %tmp12 = shl i32 %arg1, 2
+  %tmp13 = add nsw i32 %tmp12, %arg
+  br label %bb30
+
+bb14:                                             ; preds = %bb
+  %0 = and i32 %arg1, %arg
+  %1 = icmp slt i32 %0, 0
+  br i1 %1, label %bb20, label %bb26
+
+bb20:                                             ; preds = %bb14
+  %tmp22 = mul nsw i32 %arg, 3
+  %tmp24 = sdiv i32 %arg1, 6
+  %tmp25 = add nsw i32 %tmp24, %tmp22
+  br label %bb30
+
+bb26:                                             ; preds = %bb14
+  %tmp29 = sub nsw i32 %arg, %arg1
+  br label %bb30
+
+bb30:                                             ; preds = %bb26, %bb20, %bb9
+  %tmp.0 = phi i32 [ %tmp13, %bb9 ], [ %tmp25, %bb20 ], [ %tmp29, %bb26 ]
+  ret i32 %tmp.0
+}
+
diff --git a/llvm/test/Transforms/BlockExtractor/invalid-block.ll b/llvm/test/Transforms/BlockExtractor/invalid-block.ll
new file mode 100644
index 00000000000..f444764e991
--- /dev/null
+++ b/llvm/test/Transforms/BlockExtractor/invalid-block.ll
@@ -0,0 +1,9 @@
+; RUN: echo 'bar invalidbb' > %t
+; RUN: not opt -S -extract-blocks -extract-blocks-file=%t %s 2>&1 | FileCheck %s
+
+; CHECK: Invalid block
+define void @bar() {
+bb:
+  ret void
+}
+
diff --git a/llvm/test/Transforms/BlockExtractor/invalid-function.ll b/llvm/test/Transforms/BlockExtractor/invalid-function.ll
new file mode 100644
index 00000000000..4044815893e
--- /dev/null
+++ b/llvm/test/Transforms/BlockExtractor/invalid-function.ll
@@ -0,0 +1,9 @@
+; RUN: echo 'foo bb' > %t
+; RUN: not opt -S -extract-blocks -extract-blocks-file=%t %s 2>&1 | FileCheck %s
+
+; CHECK: Invalid function
+define void @bar() {
+bb:
+  ret void
+}
+