[llvm] 580d3a1 - [NFC][SCEV] `createNodeForSelectOrPHIViaUMinSeq()`: refactor `i1 cond ? i1 x : i1 y` handling

[Roman Lebedev via llvm-commits]

Author: Roman Lebedev
Date: 2022-02-10T17:42:56+03:00
New Revision: 580d3a14b2a716f31f4e4bccdb7dce4f09c7c3b7

URL: https://github.com/llvm/llvm-project/commit/580d3a14b2a716f31f4e4bccdb7dce4f09c7c3b7
DIFF: https://github.com/llvm/llvm-project/commit/580d3a14b2a716f31f4e4bccdb7dce4f09c7c3b7.diff

LOG: [NFC][SCEV] `createNodeForSelectOrPHIViaUMinSeq()`: refactor `i1 cond ? i1 x : i1 y` handling

While that effectively concludes i1 select handling,
that boolean restriction can be lifted later.

Added: 
    

Modified: 
    llvm/lib/Analysis/ScalarEvolution.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 52712757b4ae..86d0bb1249c7 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -5994,20 +5994,23 @@ const SCEV *ScalarEvolution::createNodeForSelectOrPHIViaUMinSeq(
       !FalseVal->getType()->isIntegerTy(1))
     return getUnknown(V);
 
-  // i1 cond ? i1 x : i1 C  -->  C + (umin_seq cond, x + C)
-  if (isa<ConstantInt>(FalseVal)) {
-    const SCEV *C = getSCEV(FalseVal);
-    return getAddExpr(C, getUMinExpr(getSCEV(Cond),
-                                     getAddExpr(C, getSCEV(TrueVal)),
-                                     /*Sequential=*/true));
-  }
-
-  // i1 cond ? i1 C : i1 y  -->  C + (umin_seq ~cond, y + C)
-  if (isa<ConstantInt>(TrueVal)) {
-    const SCEV *C = getSCEV(TrueVal);
-    return getAddExpr(C, getUMinExpr(getNotSCEV(getSCEV(Cond)),
-                                     getAddExpr(C, getSCEV(FalseVal)),
-                                     /*Sequential=*/true));
+  // i1 cond ? i1 x : i1 C  -->  C + (umin_seq  cond, x + C)
+  // i1 cond ? i1 C : i1 x  -->  C + (umin_seq ~cond, x + C)
+  if (isa<ConstantInt>(TrueVal) || isa<ConstantInt>(FalseVal)) {
+    const SCEV *CondExpr = getSCEV(Cond);
+    const SCEV *TrueExpr = getSCEV(TrueVal);
+    const SCEV *FalseExpr = getSCEV(FalseVal);
+    const SCEV *X, *C;
+    if (isa<ConstantInt>(TrueVal)) {
+      CondExpr = getNotSCEV(CondExpr);
+      X = FalseExpr;
+      C = TrueExpr;
+    } else {
+      X = TrueExpr;
+      C = FalseExpr;
+    }
+    return getAddExpr(
+        C, getUMinExpr(CondExpr, getAddExpr(C, X), /*Sequential=*/true));
   }
 
   return getUnknown(V);