[FastISel] Local values shouldn't be alive across an inline asm call with side effects.

This fixes an issue where a local value is defined before and used after an
inline asm call with side effects.

This fix simply flushes the local value map, which updates the insertion point
for the inline asm call to be above any previously defined local values.

This fixes <rdar://problem/17694203>

llvm-svn: 213203

diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
index f071efa..ad75e91 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -1038,6 +1038,11 @@ bool FastISel::SelectCall(const User *I) {
 
   // Handle simple inline asms.
   if (const InlineAsm *IA = dyn_cast<InlineAsm>(Call->getCalledValue())) {
+    // If the inline asm has side effects, then make sure that no local value
+    // lives across by flushing the local value map.
+    if (IA->hasSideEffects())
+      flushLocalValueMap();
+
     // Don't attempt to handle constraints.
     if (!IA->getConstraintString().empty())
       return false;

diff --git a/llvm/test/CodeGen/ARM/fast-isel-inline-asm.ll b/llvm/test/CodeGen/ARM/fast-isel-inline-asm.ll
new file mode 100644 (file)
index 0000000..2eb25ec
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/fast-isel-inline-asm.ll
@@ -0,0 +1,18 @@
+; RUN: llc -fast-isel < %s | FileCheck %s
+target datalayout = "e-m:o-p:32:32-i1:8:32-i8:8:32-i16:16:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"
+target triple = "thumbv7-apple-ios5.0.0"
+
+%0 = type opaque
+
+; Make sure that the inline asm starts right after the call to bar.
+define void @test_inline_asm_sideeffect(%0* %call) {
+; CHECK:      bl _bar
+; CHECK-NEXT: InlineAsm Start
+  call void @bar()
+  call void asm sideeffect "mov\09r7, r7\09\09@ marker", ""()
+  %1 = call %0* bitcast (i8* (i8*)* @foo to %0* (%0*)*)(%0* %call)
+  ret void
+}
+
+declare i8* @foo(i8*)
+declare void @bar()