[llvm] [X86] Remove redundant TEST after shifts when count is non-zero (PR #169069)

[Matt Arsenault via llvm-commits]

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@@ -786,8 +786,32 @@ bool CodeGenPrepare::eliminateAssumptions(Function &F) {
       if (auto *Assume = dyn_cast<AssumeInst>(I)) {
         MadeChange = true;
         Value *Operand = Assume->getOperand(0);
+        if (ICmpInst *Cmp = dyn_cast<ICmpInst>(Operand)) {
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arsenm wrote:

CodeGenPrepare doesn't feel like the right place for this 

https://github.com/llvm/llvm-project/pull/169069