[llvm] r370753 - [SystemZ] Recognize INLINEASM_BR in backend.

[Jonas Paulsson via llvm-commits]

Author: jonpa
Date: Tue Sep  3 06:31:22 2019
New Revision: 370753

URL: http://llvm.org/viewvc/llvm-project?rev=370753&view=rev
Log:
[SystemZ]  Recognize INLINEASM_BR in backend.

SystemZInstrInfo::analyzeBranch() needs to check for INLINEASM_BR
instructions, or it will crash.

Review: Ulrich Weigand

Added:
    llvm/trunk/test/CodeGen/SystemZ/asm-20.ll
Modified:
    llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp

Modified: llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp?rev=370753&r1=370752&r2=370753&view=diff
==============================================================================
--- llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp Tue Sep  3 06:31:22 2019
@@ -462,8 +462,8 @@ bool SystemZInstrInfo::analyzeBranch(Mac
       break;
 
     // A terminator that isn't a branch can't easily be handled by this
-    // analysis.
-    if (!I->isBranch())
+    // analysis.  Asm goto is not understood / optimized.
+    if (!I->isBranch() || I->getOpcode() == SystemZ::INLINEASM_BR)
       return true;
 
     // Can't handle indirect branches.

Added: llvm/trunk/test/CodeGen/SystemZ/asm-20.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/SystemZ/asm-20.ll?rev=370753&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/SystemZ/asm-20.ll (added)
+++ llvm/trunk/test/CodeGen/SystemZ/asm-20.ll Tue Sep  3 06:31:22 2019
@@ -0,0 +1,15 @@
+; Test that asm goto can be compiled.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu
+
+define i32 @c() {
+entry:
+  callbr void asm sideeffect "", "X"(i8* blockaddress(@c, %d))
+          to label %asm.fallthrough [label %d]
+
+asm.fallthrough:               ; preds = %entry
+  br label %d
+
+d:                             ; preds = %asm.fallthrough, %entry
+  ret i32 undef
+}