[llvm] [LV] Add extra check for signed oveflow for SDiv/SRem (PR #170818)

[Luke Lau via llvm-commits]

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@@ -599,7 +600,8 @@ define void @predicated_sdiv_by_minus_one(ptr noalias nocapture %a, i64 %n) {
 ; FIXED-NEXT:    [[WIDE_LOAD1:%.*]] = load <32 x i8>, ptr [[TMP1]], align 1
 ; FIXED-NEXT:    [[TMP5:%.*]] = icmp ne <32 x i8> [[WIDE_LOAD1]], splat (i8 -128)
 ; FIXED-NEXT:    [[TMP7:%.*]] = select <32 x i1> [[TMP5]], <32 x i8> splat (i8 -1), <32 x i8> splat (i8 1)
-; FIXED-NEXT:    [[TMP9:%.*]] = sdiv <32 x i8> [[WIDE_LOAD1]], [[TMP7]]
+; FIXED-NEXT:    [[TMP3:%.*]] = select <32 x i1> [[TMP5]], <32 x i8> [[WIDE_LOAD1]], <32 x i8> zeroinitializer
+; FIXED-NEXT:    [[TMP9:%.*]] = sdiv <32 x i8> [[TMP3]], [[TMP7]]
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lukel97 wrote:

It looks like these tests all got predicated previously anyway. I think we need to add a new test where the divisor is loop invariant and the division isn't in a predicated block

https://github.com/llvm/llvm-project/pull/170818