From: Chris Lattner <sabre@nondot.org>
Date: Thu, 21 Apr 2005 05:43:13 +0000 (+0000)
Subject: Instcombine this:
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=956db27a63a5f105c12787098dbe713747ed0528;p=oota-llvm.git

Instcombine this:

        %shortcirc_val = select bool %tmp.1, bool true, bool %tmp.4             ; <bool> [#uses=1]
        %tmp.6 = cast bool %shortcirc_val to int                ; <int> [#uses=1]

into this:

        %shortcirc_val = or bool %tmp.1, %tmp.4         ; <bool> [#uses=1]
        %tmp.6 = cast bool %shortcirc_val to int                ; <int> [#uses=1]

not this:

        %tmp.4.cast = cast bool %tmp.4 to int           ; <int> [#uses=1]
        %tmp.6 = select bool %tmp.1, int 1, int %tmp.4.cast             ; <int> [#uses=1]


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21389 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 6c1284cbd52..fcdd73d0a66 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -548,6 +548,9 @@ static Instruction *FoldOpIntoSelect(Instruction &Op, SelectInst *SI,
   Value *FV = SI->getOperand(2);
 
   if (isa<Constant>(TV) || isa<Constant>(FV)) {
+    // Bool selects with constant operands can be folded to logical ops.
+    if (SI->getType() == Type::BoolTy) return 0;
+
     Value *SelectTrueVal = FoldOperationIntoSelectOperand(Op, TV, IC);
     Value *SelectFalseVal = FoldOperationIntoSelectOperand(Op, FV, IC);