[CGP] Add pre-commit test for Fix matching of uadd overflow

Add tests 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.

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

Author: vladimirradosavljevic

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

@@ -0,0 +1,55 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt -codegenprepare --cgp-verify-bfi-updates=false -S < %s | FileCheck %s
+; Verification of BFI updates is disabled because of https://github.com/llvm/llvm-project/issues/64197
+
+target datalayout = "E-p:256:256-i256:256:256-S32-a:256:256"
+target triple = "eravm"
+
+define i256 @dont_match(i256 %a) {
+; CHECK-LABEL: define i256 @dont_match
+; CHECK-SAME: (i256 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = call { i256, i1 } @llvm.uadd.with.overflow.i256(i256 [[A]], i256 18446744073709551615)
+; CHECK-NEXT:    [[MATH:%.*]] = extractvalue { i256, i1 } [[TMP0]], 0
+; CHECK-NEXT:    [[OV:%.*]] = extractvalue { i256, i1 } [[TMP0]], 1
+; CHECK-NEXT:    br i1 [[OV]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK:       then:
+; CHECK-NEXT:    ret i256 0
+; CHECK:       else:
+; CHECK-NEXT:    ret i256 [[MATH]]
+;
+entry:
+  %add = add i256 %a, 18446744073709551615
+  %cmp = icmp ne i256 %a, 0
+  br i1 %cmp, label %then, label %else
+
+then:
+  ret i256 0
+
+else:
+  ret i256 %add
+}
+
+define i256 @match(i256 %a) {
+; CHECK-LABEL: define i256 @match
+; CHECK-SAME: (i256 [[A:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[ADD:%.*]] = add i256 [[A]], -1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i256 [[A]], 0
+; CHECK-NEXT:    br i1 [[CMP]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK:       then:
+; CHECK-NEXT:    ret i256 0
+; CHECK:       else:
+; CHECK-NEXT:    ret i256 [[ADD]]
+;
+entry:
+  %add = add i256 %a, -1
+  %cmp = icmp ne i256 %a, 0
+  br i1 %cmp, label %then, label %else
+
+then:
+  ret i256 0
+
+else:
+  ret i256 %add
+}