[llvm-commits] [llvm] r45613 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/2007-12-19-IcmpSub.ll

[Chris Lattner]

Author: lattner
Date: Fri Jan  4 19:22:42 2008
New Revision: 45613

URL: http://llvm.org/viewvc/llvm-project?rev=45613&view=rev
Log:
remove a couple more unsafe xforms in the face of overflow.

Removed:
    llvm/trunk/test/Transforms/InstCombine/2007-12-19-IcmpSub.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=45613&r1=45612&r2=45613&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Fri Jan  4 19:22:42 2008
@@ -4865,10 +4865,6 @@
         return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1);
       if (isMinValuePlusOne(CI,true))              // A <s MIN+1 -> A == MIN
         return new ICmpInst(ICmpInst::ICMP_EQ, Op0, SubOne(CI));
-      
-      // (icmp slt (sub A B) 1) -> (icmp sle A B)
-      if (CI->isOne() && match(Op0, m_Sub(m_Value(A), m_Value(B))))
-        return new ICmpInst(ICmpInst::ICMP_SLE, A, B);
       break;
 
     case ICmpInst::ICMP_UGT:
@@ -4892,11 +4888,6 @@
         return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1);
       if (isMaxValueMinusOne(CI, true))           // A >s MAX-1 -> A == MAX
         return new ICmpInst(ICmpInst::ICMP_EQ, Op0, AddOne(CI));
-      
-      // (icmp sgt (sub A B) -1) -> (icmp sge A B)
-      if (CI->getValue().getSExtValue() == -1 && 
-          match(Op0, m_Sub(m_Value(A), m_Value(B))))
-        return new ICmpInst(ICmpInst::ICMP_SGE, A, B);
       break;
 
     case ICmpInst::ICMP_ULE:

Removed: llvm/trunk/test/Transforms/InstCombine/2007-12-19-IcmpSub.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2007-12-19-IcmpSub.ll?rev=45612&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2007-12-19-IcmpSub.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/2007-12-19-IcmpSub.ll (removed)
@@ -1,25 +0,0 @@
-; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep {sub}
-
-define i32 @foo(i32 %a) {
-entry:
-	%tmp2 = sub i32 99, %a		; <i32> [#uses=1]
-	%tmp3 = icmp sgt i32 %tmp2, -1		; <i1> [#uses=1]
-	%retval = select i1 %tmp3, i32 %a, i32 0		; <i32> [#uses=1]
-	ret i32 %retval
-}
-
-define i32 @bar(i32 %a) {
-entry:
-	%tmp2 = sub i32 99, %a		; <i32> [#uses=1]
-	%tmp3 = icmp sge i32 %tmp2, 0; <i1> [#uses=1]
-	%retval = select i1 %tmp3, i32 %a, i32 0		; <i32> [#uses=1]
-	ret i32 %retval
-}
-
-define i32 @baz(i32 %a) {
-entry:
-	%tmp2 = sub i32 99, %a		; <i32> [#uses=1]
-	%tmp3 = icmp slt i32 %tmp2, 1		; <i1> [#uses=1]
-	%retval = select i1 %tmp3, i32 %a, i32 0		; <i32> [#uses=1]
-	ret i32 %retval
-}
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