[CGP] Fix matching of uadd overflow

This patch fixes the issue where uadd overflow
intrinsic is matched for:
`Add = add A,(uint64_t)-1; Cmp = icmp ne A, 0`
instead of:
`Add = add A,-1; Cmp = icmp ne A, 0`
where -1 is represented in 256 bits.

PR: #626

Signed-off-by: Vladimir Radosavljevic <[email protected]>

Author: vladimirradosavljevic

llvm/lib/CodeGen/CodeGenPrepare.cpp

@@ -1584,7 +1584,9 @@ static bool matchUAddWithOverflowConstantEdgeCases(CmpInst *Cmp,
   if (Pred == ICmpInst::ICMP_EQ && match(B, m_AllOnes()))
     B = ConstantInt::get(B->getType(), 1);
   else if (Pred == ICmpInst::ICMP_NE && match(B, m_ZeroInt()))
-    B = ConstantInt::get(B->getType(), -1);
+    // EraVM local begin
+    B = ConstantInt::get(B->getType(), -1, true);
+    // EraVM local end
   else
     return false;
 

llvm/test/CodeGen/EraVM/cgp-uadd-overflow-wrong-match.ll

@@ -10,13 +10,10 @@ define i256 @dont_match(i256 %a) {
 ; CHECK:       ; %bb.0: ; %entry
 ; CHECK-NEXT:    add r1, r0, r2
 ; CHECK-NEXT:    add @CPI0_0[0], r2, r1
-; CHECK-NEXT:    add! @CPI0_0[0], r2, r2
-; CHECK-NEXT:    jump.lt @.BB0_2
+; CHECK-NEXT:    sub! r2, r0, r2
+; CHECK-NEXT:    add.ne r0, r0, r1
 ; CHECK-NEXT:  ; %bb.1: ; %else
 ; CHECK-NEXT:    ret
-; CHECK-NEXT:  .BB0_2: ; %then
-; CHECK-NEXT:    add r0, r0, r1
-; CHECK-NEXT:    ret
 entry:
   %add = add i256 %a, 18446744073709551615
   %cmp = icmp ne i256 %a, 0
@@ -32,9 +29,13 @@ else:
 define i256 @match(i256 %a) {
 ; CHECK-LABEL: match:
 ; CHECK:       ; %bb.0: ; %entry
-; CHECK-NEXT:    sub! r1, r0, r2
-; CHECK-NEXT:    sub.s.eq 1, r1, r1
-; CHECK-NEXT:    add.ne r0, r0, r1
+; CHECK-NEXT:    add! @CPI1_0[0], r1, r2
+; CHECK-NEXT:    jump.lt @.BB1_2
+; CHECK-NEXT:  ; %bb.1: ; %else
+; CHECK-NEXT:    sub.s 1, r1, r1
+; CHECK-NEXT:    ret
+; CHECK-NEXT:  .BB1_2: ; %then
+; CHECK-NEXT:    add r0, r0, r1
 ; CHECK-NEXT:    ret
 entry:
   %add = add i256 %a, -1