Include SelectionDAGISel in the opt-bisect process

Differential Revision: http://reviews.llvm.org/D21143



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274786 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Andrew Kaylor

lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

@@ -443,7 +443,7 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
   TM.resetTargetOptions(Fn);
   // Reset OptLevel to None for optnone functions.
   CodeGenOpt::Level NewOptLevel = OptLevel;
-  if (Fn.hasFnAttribute(Attribute::OptimizeNone))
+  if (OptLevel != CodeGenOpt::None && skipFunction(Fn))
     NewOptLevel = CodeGenOpt::None;
   OptLevelChanger OLC(*this, NewOptLevel);
 

test/Other/X86/opt-bisect-isel.ll

@@ -0,0 +1,22 @@
+; This test verifies that no optimizations are performed on the @f function
+; when the -opt-bisect-limit=0 option is used.  In particular, the X86
+; instruction selector will optimize the cmp instruction to a sub instruction
+; if it is not run in -O0 mode.
+
+; RUN: llc -O3 -opt-bisect-limit=0 -o - %s | FileCheck %s
+
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @f() {
+entry:
+  %cmp = icmp slt i32 undef, 8
+  br i1 %cmp, label %middle, label %end
+
+middle:
+  br label %end
+
+end:
+  ret void
+}
+
+; CHECK: cmpl $8, %eax