[llvm] [InstCombine] Extend Phi-Icmp use to include or (PR #67682)

[Nikita Popov via llvm-commits]

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@@ -1286,6 +1286,248 @@ if.end:                                           ; preds = %entry, %if.then
   ret i1  %cmp1
 }
 
+define i1 @phi_knownnonzero_eq_oricmp(i32 %n, i32 %s, ptr nocapture readonly %P, i32 %val) {
+; CHECK-LABEL: @phi_knownnonzero_eq_oricmp(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp slt i32 [[N:%.*]], [[S:%.*]]
+; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    [[A_0:%.*]] = phi i32 [ 1, [[IF_THEN]] ], [ [[N]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[TMP0:%.*]] = or i32 [[A_0]], [[VAL:%.*]]
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i32 [[TMP0]], 0
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+entry:
+  %tobool = icmp slt  i32 %n, %s
+  br i1 %tobool, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  %0 = load i32, ptr %P
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nikic wrote:

Name instructions.

https://github.com/llvm/llvm-project/pull/67682