Fix pr4552. Stack slot coloring with register must take care not to generate illegal ams.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76258 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 71 insertions, 0 deletions

diff --git a/lib/CodeGen/StackSlotColoring.cpp b/lib/CodeGen/StackSlotColoring.cpp
index 582464478c..0d9ebbbeb8 100644
--- a/lib/CodeGen/StackSlotColoring.cpp
+++ b/lib/CodeGen/StackSlotColoring.cpp
@@ -503,6 +503,15 @@ bool StackSlotColoring::PropagateBackward(MachineBasicBlock::iterator MII,
       if (Reg == OldReg) {
         if (MO.isImplicit())
           return false;
+
+        // Abort the use is actually a sub-register def. We don't have enough
+        // information to figure out if it is really legal.
+        if (MO.getSubReg() ||
+            TID.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
+            TID.getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
+            TID.getOpcode() == TargetInstrInfo::SUBREG_TO_REG)
+          return false;
+
         const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, TID, i);
         if (RC && !RC->contains(NewReg))
           return false;
@@ -561,12 +570,19 @@ bool StackSlotColoring::PropagateForward(MachineBasicBlock::iterator MII,
         if (MO.isDef() || MO.isImplicit())
           return false;
 
+        // Abort the use is actually a sub-register use. We don't have enough
+        // information to figure out if it is really legal.
+        if (MO.getSubReg() ||
+            TID.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG)
+          return false;
+
         const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, TID, i);
         if (RC && !RC->contains(NewReg))
           return false;
         FoundUse = true;
         if (MO.isKill())
           FoundKill = true;
+
         Uses.push_back(&MO);
       } else if (TRI->regsOverlap(Reg, NewReg) ||
                  TRI->regsOverlap(Reg, OldReg))
diff --git a/test/CodeGen/X86/2009-07-17-StackColoringBug.ll b/test/CodeGen/X86/2009-07-17-StackColoringBug.ll
new file mode 100644
index 0000000000..172b6ec78c
--- /dev/null
+++ b/test/CodeGen/X86/2009-07-17-StackColoringBug.ll
@@ -0,0 +1,55 @@
+; RUN: llvm-as < %s | llc -mtriple=i386-pc-linux-gnu -disable-fp-elim -color-ss-with-regs | not grep dil
+; PR4552
+
+target triple = "i386-pc-linux-gnu"
+@g_8 = internal global i32 0		; <i32*> [#uses=1]
+@g_72 = internal global i32 0		; <i32*> [#uses=1]
+@llvm.used = appending global [1 x i8*] [i8* bitcast (i32 (i32, i8, i8)* @uint84 to i8*)], section "llvm.metadata"		; <[1 x i8*]*> [#uses=0]
+
+define i32 @uint84(i32 %p_15, i8 signext %p_17, i8 signext %p_19) nounwind {
+entry:
+	%g_72.promoted = load i32* @g_72		; <i32> [#uses=1]
+	%g_8.promoted = load i32* @g_8		; <i32> [#uses=1]
+	br label %bb
+
+bb:		; preds = %func_40.exit, %entry
+	%g_8.tmp.1 = phi i32 [ %g_8.promoted, %entry ], [ %g_8.tmp.0, %func_40.exit ]		; <i32> [#uses=3]
+	%g_72.tmp.1 = phi i32 [ %g_72.promoted, %entry ], [ %g_72.tmp.0, %func_40.exit ]		; <i32> [#uses=3]
+	%retval12.i4.i.i = trunc i32 %g_8.tmp.1 to i8		; <i8> [#uses=2]
+	%0 = trunc i32 %g_72.tmp.1 to i8		; <i8> [#uses=2]
+	%1 = mul i8 %retval12.i4.i.i, %0		; <i8> [#uses=1]
+	%2 = icmp eq i8 %1, 0		; <i1> [#uses=1]
+	br i1 %2, label %bb2.i.i, label %bb.i.i
+
+bb.i.i:		; preds = %bb
+	%3 = sext i8 %0 to i32		; <i32> [#uses=1]
+	%4 = and i32 %3, 50295		; <i32> [#uses=1]
+	%5 = icmp eq i32 %4, 0		; <i1> [#uses=1]
+	br i1 %5, label %bb2.i.i, label %func_55.exit.i
+
+bb2.i.i:		; preds = %bb.i.i, %bb
+	br label %func_55.exit.i
+
+func_55.exit.i:		; preds = %bb2.i.i, %bb.i.i
+	%g_72.tmp.2 = phi i32 [ 1, %bb2.i.i ], [ %g_72.tmp.1, %bb.i.i ]		; <i32> [#uses=1]
+	%6 = phi i32 [ 1, %bb2.i.i ], [ %g_72.tmp.1, %bb.i.i ]		; <i32> [#uses=1]
+	%7 = trunc i32 %6 to i8		; <i8> [#uses=2]
+	%8 = mul i8 %7, %retval12.i4.i.i		; <i8> [#uses=1]
+	%9 = icmp eq i8 %8, 0		; <i1> [#uses=1]
+	br i1 %9, label %bb2.i4.i, label %bb.i3.i
+
+bb.i3.i:		; preds = %func_55.exit.i
+	%10 = sext i8 %7 to i32		; <i32> [#uses=1]
+	%11 = and i32 %10, 50295		; <i32> [#uses=1]
+	%12 = icmp eq i32 %11, 0		; <i1> [#uses=1]
+	br i1 %12, label %bb2.i4.i, label %func_40.exit
+
+bb2.i4.i:		; preds = %bb.i3.i, %func_55.exit.i
+	br label %func_40.exit
+
+func_40.exit:		; preds = %bb2.i4.i, %bb.i3.i
+	%g_72.tmp.0 = phi i32 [ 1, %bb2.i4.i ], [ %g_72.tmp.2, %bb.i3.i ]		; <i32> [#uses=1]
+	%phitmp = icmp sgt i32 %g_8.tmp.1, 0		; <i1> [#uses=1]
+	%g_8.tmp.0 = select i1 %phitmp, i32 %g_8.tmp.1, i32 1		; <i32> [#uses=1]
+	br label %bb
+}