diff --git a/collects/tests/typed-scheme/optimizer/tests/bounds-check.rkt b/collects/tests/typed-scheme/optimizer/tests/bounds-check.rkt
index 298cb77ba3..94a7697749 100644
--- a/collects/tests/typed-scheme/optimizer/tests/bounds-check.rkt
+++ b/collects/tests/typed-scheme/optimizer/tests/bounds-check.rkt
@@ -1,13 +1,13 @@
 #;
 (
-TR opt: bounds-check.rkt 25:2 (vector-ref v i) -- vector access splitting
-TR opt: bounds-check.rkt 28:2 (vector-set! v i n) -- vector access splitting
-TR opt: bounds-check.rkt 31:2 (vector-ref v i) -- vector access splitting
-TR opt: bounds-check.rkt 34:2 (vector-set! v i n) -- vector access splitting
-TR opt: bounds-check.rkt 46:2 (flvector-ref v i) -- flvector access splitting
-TR opt: bounds-check.rkt 49:2 (flvector-set! v i n) -- flvector access splitting
-TR opt: bounds-check.rkt 52:2 (flvector-ref v i) -- flvector access splitting
-TR opt: bounds-check.rkt 55:2 (flvector-set! v i n) -- flvector access splitting
+TR opt: bounds-check.rkt 25:2 (vector-ref v i) -- vector partial bounds checking elimination
+TR opt: bounds-check.rkt 28:2 (vector-set! v i n) -- vector partial bounds checking elimination
+TR opt: bounds-check.rkt 31:2 (vector-ref v i) -- vector partial bounds checking elimination
+TR opt: bounds-check.rkt 34:2 (vector-set! v i n) -- vector partial bounds checking elimination
+TR opt: bounds-check.rkt 46:2 (flvector-ref v i) -- flvector partial bounds checking elimination
+TR opt: bounds-check.rkt 49:2 (flvector-set! v i n) -- flvector partial bounds checking elimination
+TR opt: bounds-check.rkt 52:2 (flvector-ref v i) -- flvector partial bounds checking elimination
+TR opt: bounds-check.rkt 55:2 (flvector-set! v i n) -- flvector partial bounds checking elimination
 3
 4
 5
diff --git a/collects/tests/typed-scheme/optimizer/tests/invalid-vector-ref.rkt b/collects/tests/typed-scheme/optimizer/tests/invalid-vector-ref.rkt
index b6fadfbb74..368664ea98 100644
--- a/collects/tests/typed-scheme/optimizer/tests/invalid-vector-ref.rkt
+++ b/collects/tests/typed-scheme/optimizer/tests/invalid-vector-ref.rkt
@@ -1,6 +1,6 @@
 #;
 (
-TR opt: invalid-vector-ref.rkt 10:2 (vector-ref x 0) -- vector access splitting
+TR opt: invalid-vector-ref.rkt 10:2 (vector-ref x 0) -- vector partial bounds checking elimination
 )
 
 #lang typed/scheme
diff --git a/collects/tests/typed-scheme/optimizer/tests/invalid-vector-set.rkt b/collects/tests/typed-scheme/optimizer/tests/invalid-vector-set.rkt
index 71c127753b..7f3cfede03 100644
--- a/collects/tests/typed-scheme/optimizer/tests/invalid-vector-set.rkt
+++ b/collects/tests/typed-scheme/optimizer/tests/invalid-vector-set.rkt
@@ -1,6 +1,6 @@
 #;
 (
-TR opt: invalid-vector-set.rkt 10:2 (vector-set! x 0 2) -- vector access splitting
+TR opt: invalid-vector-set.rkt 10:2 (vector-set! x 0 2) -- vector partial bounds checking elimination
 )
 
 #lang typed/scheme
diff --git a/collects/tests/typed-scheme/optimizer/tests/vector-sum.rkt b/collects/tests/typed-scheme/optimizer/tests/vector-sum.rkt
index 6475adcceb..0738cd619e 100644
--- a/collects/tests/typed-scheme/optimizer/tests/vector-sum.rkt
+++ b/collects/tests/typed-scheme/optimizer/tests/vector-sum.rkt
@@ -1,29 +1,29 @@
 #;
 (
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
-TR opt: vector-sum.rkt 39:2 (for: ((i : Nonnegative-Fixnum (in-range l))) (vector-set! v i (sin (exact->inexact i)))) -- binary fixnum
-TR opt: vector-sum.rkt 39:2 (for: ((i : Nonnegative-Fixnum (in-range l))) (vector-set! v i (sin (exact->inexact i)))) -- dead else branch
-TR opt: vector-sum.rkt 39:2 (for: ((i : Nonnegative-Fixnum (in-range l))) (vector-set! v i (sin (exact->inexact i)))) -- dead else branch
-TR opt: vector-sum.rkt 39:2 (for: ((i : Nonnegative-Fixnum (in-range l))) (vector-set! v i (sin (exact->inexact i)))) -- fixnum bounded expr
-TR opt: vector-sum.rkt 41:2 (for/fold: ((sum : Float 0.0)) ((i : Nonnegative-Fixnum (in-range l))) (+ sum (vector-ref v i))) -- binary fixnum
 TR opt: vector-sum.rkt 41:2 (for/fold: ((sum : Float 0.0)) ((i : Nonnegative-Fixnum (in-range l))) (+ sum (vector-ref v i))) -- fixnum bounded expr
-TR opt: vector-sum.rkt 40:4 (vector-set! v i (sin (exact->inexact i))) -- vector access splitting
-TR opt: vector-sum.rkt 40:22 sin -- unary float
-TR opt: vector-sum.rkt 40:27 exact->inexact -- fixnum to float
+TR opt: vector-sum.rkt 41:2 (for/fold: ((sum : Float 0.0)) ((i : Nonnegative-Fixnum (in-range l))) (+ sum (vector-ref v i))) -- binary fixnum
+TR opt: vector-sum.rkt 39:2 (for: ((i : Nonnegative-Fixnum (in-range l))) (vector-set! v i (sin (exact->inexact i)))) -- fixnum bounded expr
+TR opt: vector-sum.rkt 39:2 (for: ((i : Nonnegative-Fixnum (in-range l))) (vector-set! v i (sin (exact->inexact i)))) -- binary fixnum
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 39:2 (for: ((i : Nonnegative-Fixnum (in-range l))) (vector-set! v i (sin (exact->inexact i)))) -- dead else branch
+TR opt: vector-sum.rkt 39:2 (for: ((i : Nonnegative-Fixnum (in-range l))) (vector-set! v i (sin (exact->inexact i)))) -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 29:0 #%module-begin -- dead else branch
+TR opt: vector-sum.rkt 40:4 (vector-set! v i (sin (exact->inexact i))) -- vector partial bounds checking elimination
+TR opt: vector-sum.rkt 40:21 (sin (exact->inexact i)) -- unary float
+TR opt: vector-sum.rkt 40:26 (exact->inexact i) -- fixnum to float
 TR opt: vector-sum.rkt 41:15 sum -- dead else branch
 TR opt: vector-sum.rkt 41:15 sum -- dead else branch
-TR opt: vector-sum.rkt 43:5 + -- binary float
-TR opt: vector-sum.rkt 43:11 (vector-ref v i) -- vector access splitting
+TR opt: vector-sum.rkt 43:4 (+ sum (vector-ref v i)) -- binary float
+TR opt: vector-sum.rkt 43:11 (vector-ref v i) -- vector partial bounds checking elimination
 )
 
 #lang typed/racket
diff --git a/collects/typed-scheme/optimizer/vector.rkt b/collects/typed-scheme/optimizer/vector.rkt
index 52e62600b0..329df5a30e 100644
--- a/collects/typed-scheme/optimizer/vector.rkt
+++ b/collects/typed-scheme/optimizer/vector.rkt
@@ -74,7 +74,9 @@
   ;; we can do the bounds checking separately, to eliminate some of the checks
   (pattern (#%plain-app op:vector-op v:expr i:fixnum-expr new:expr ...)
            #:with opt
-           (begin (log-optimization "vector access splitting" this-syntax)
+           (begin (log-optimization "vector partial bounds checking elimination"
+                                    "Partial bounds checking elimination."
+                                    this-syntax)
                   (let ([safe-fallback #`(op new-v new-i #,@(syntax-map (optimize) #'(new ...)))]
                         [i-known-nonneg? (subtypeof? #'i -NonNegFixnum)])
                     #`(let ([new-i #,((optimize) #'i)]
@@ -100,7 +102,9 @@
   ;; similarly for flvectors
   (pattern (#%plain-app op:flvector-op v:expr i:fixnum-expr new:expr ...)
            #:with opt
-           (begin (log-optimization "flvector access splitting" this-syntax)
+           (begin (log-optimization "flvector partial bounds checking elimination"
+                                    "Partial bounds checking elimination."
+                                    this-syntax)
                   (let ([safe-fallback #`(op new-v new-i #,@(syntax-map (optimize) #'(new ...)))]
                         [i-known-nonneg? (subtypeof? #'i -NonNegFixnum)])
                     #`(let ([new-i #,((optimize) #'i)]