[PATCH] D60020: [DAGCombiner][X86] Canonicalize SSUBO with immediate RHS to SADDO by negating the immediate.

[Craig Topper via Phabricator via llvm-commits]

craig.topper marked an inline comment as done.
craig.topper added inline comments.


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Comment at: llvm/test/CodeGen/X86/sub-with-overflow.ll:86
 ; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    cmpl $1, {{[0-9]+}}(%esp)
+; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; CHECK-NEXT:    decl %eax
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This is somewhat a regression, but we now generate the code we would get from sadd.with.overflow.i32 with an immediate of -1. So we probably need a more complete canonicalization to icmp when the data result isn't used.


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  https://reviews.llvm.org/D60020/new/

https://reviews.llvm.org/D60020