Fix PR 4057, a crash doing float->char const folding.

This particular one is undefined behavior (although this
isn't related to the crash), so it will no longer do it
at compile time, which seems better.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69990 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index edd985ed1ad7dfde7866bc9fa89788418d534fb1..954b84233bb832a8212a0748e1819aed8144e1e1 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2197,16 +2197,17 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL,
       }
       case ISD::FP_TO_SINT:
       case ISD::FP_TO_UINT: {
-        integerPart x;
+        integerPart x[2];
         bool ignored;
         assert(integerPartWidth >= 64);
         // FIXME need to be more flexible about rounding mode.
-        APFloat::opStatus s = V.convertToInteger(&x, 64U,
+        APFloat::opStatus s = V.convertToInteger(x, VT.getSizeInBits(),
                               Opcode==ISD::FP_TO_SINT,
                               APFloat::rmTowardZero, &ignored);
         if (s==APFloat::opInvalidOp)     // inexact is OK, in fact usual
           break;
-        return getConstant(x, VT);
+        APInt api(VT.getSizeInBits(), 2, x);
+        return getConstant(api, VT);
       }
       case ISD::BIT_CONVERT:
         if (VT == MVT::i32 && C->getValueType(0) == MVT::f32)

diff --git a/test/CodeGen/Generic/fp-to-int-invalid.ll b/test/CodeGen/Generic/fp-to-int-invalid.ll
new file mode 100644 (file)
index 0000000..73176b1
--- /dev/null
+++ b/test/CodeGen/Generic/fp-to-int-invalid.ll
@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s | llc
+; PR4057
+define void @test_cast_float_to_char(i8* %result) nounwind {
+entry:
+       %result_addr = alloca i8*               ; <i8**> [#uses=2]
+       %test = alloca float            ; <float*> [#uses=2]
+       %"alloca point" = bitcast i32 0 to i32          ; <i32> [#uses=0]
+       store i8* %result, i8** %result_addr
+       store float 0x40B2AFA160000000, float* %test, align 4
+       %0 = load float* %test, align 4         ; <float> [#uses=1]
+       %1 = fptosi float %0 to i8              ; <i8> [#uses=1]
+       %2 = load i8** %result_addr, align 4            ; <i8*> [#uses=1]
+       store i8 %1, i8* %2, align 1
+       br label %return
+
+return:                ; preds = %entry
+       ret void
+}