[PATCH] D66612: [Reassoc] Small fix to support unary FNeg in NegateValue(...)

[Cameron McInally via Phabricator via llvm-commits]

cameron.mcinally created this revision.
cameron.mcinally added reviewers: mcberg2017, spatel.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.

Here's a small patch to fix an assert in `NegateValue(...)`.

This may need further performance improvements...


Repository:
  rL LLVM

https://reviews.llvm.org/D66612

Files:
  llvm/lib/Transforms/Scalar/Reassociate.cpp
  llvm/test/Transforms/Reassociate/2019-08-22-FNegAssert.ll


Index: llvm/test/Transforms/Reassociate/2019-08-22-FNegAssert.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/Reassociate/2019-08-22-FNegAssert.ll
@@ -0,0 +1,13 @@
+; RUN: opt < %s -reassociate -disable-output
+; D61675
+
+define float @test1(float %arg, float %arg1, float %arg2, float %arg3) {
+  %tmp1 = fsub fast float %arg3, %arg2
+  %tmp2 = fadd fast float %arg, -5.000000e+02
+  %tmp3 = fsub fast float %tmp1, %tmp2
+  %tmp4 = fmul fast float %tmp3, %tmp3
+  %tmp5 = fneg fast float %arg
+  %tmp6 = fdiv fast float %tmp5, %arg1
+  %tmp7 = fadd fast float %tmp6, %tmp4
+  ret float %tmp7
+}
Index: llvm/lib/Transforms/Scalar/Reassociate.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/Reassociate.cpp
+++ llvm/lib/Transforms/Scalar/Reassociate.cpp
@@ -861,7 +861,7 @@
     // this use.  We do this by moving it to the entry block (if it is a
     // non-instruction value) or right after the definition.  These negates will
     // be zapped by reassociate later, so we don't need much finesse here.
-    BinaryOperator *TheNeg = cast<BinaryOperator>(U);
+    Instruction *TheNeg = cast<Instruction>(U);
 
     // Verify that the negate is in this function, V might be a constant expr.
     if (TheNeg->getParent()->getParent() != BI->getParent()->getParent())


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