[ConstraintElim] Remove dead code. NFC.

[dtcxzyw]

R2 should be always greater than R1 here.
Code coverage: https://dtcxzyw.github.io/llvm-opt-benchmark/coverage/data/zyw/opt-ci/actions-runner/_work/llvm-opt-benchmark/llvm-opt-benchmark/llvm/llvm-project/llvm/lib/Analysis/ConstraintSystem.cpp.html#L56

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: Yingwei Zheng (dtcxzyw)

Changes

R2 should be always greater than R1 here.
Code coverage: https://dtcxzyw.github.io/llvm-opt-benchmark/coverage/data/zyw/opt-ci/actions-runner/_work/llvm-opt-benchmark/llvm-opt-benchmark/llvm/llvm-project/llvm/lib/Analysis/ConstraintSystem.cpp.html#L56

---

Full diff: https://github.com/llvm/llvm-project/pull/118983.diff

1 Files Affected:

• (modified) llvm/lib/Analysis/ConstraintSystem.cpp (-3)

diff --git a/llvm/lib/Analysis/ConstraintSystem.cpp b/llvm/lib/Analysis/ConstraintSystem.cpp
index e4c9dcc7544e99..7216a0219080f4 100644
--- a/llvm/lib/Analysis/ConstraintSystem.cpp
+++ b/llvm/lib/Analysis/ConstraintSystem.cpp
@@ -52,9 +52,6 @@ bool ConstraintSystem::eliminateUsingFM() {
   for (unsigned R1 = 0; R1 < NumRemainingConstraints; R1++) {
     // FIXME do not use copy
     for (unsigned R2 = R1 + 1; R2 < NumRemainingConstraints; R2++) {
-      if (R1 == R2)
-        continue;
-
       int64_t UpperLast = getLastCoefficient(RemainingRows[R2], LastIdx);
       int64_t LowerLast = getLastCoefficient(RemainingRows[R1], LastIdx);
       assert(

[fhahn]

might be worth adding an assert initially?

[dtcxzyw]

It is safe to remove this because R1 and R2 are both not modified inside the loop.

[fhahn]

Ah yes, thanks for the cleanup!

[nikic]

LGTM

[fhahn]

LGTM, thanks for the cleanup!

[fhahn]

Ah yes, thanks for the cleanup!