[llvm] 2b3a4c7 - [test] Extend negative stride backedge tests to cover signed comparisons
Philip Reames via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 16 10:29:38 PDT 2021
Author: Philip Reames
Date: 2021-07-16T10:29:22-07:00
New Revision: 2b3a4c7d72be4fd6792ea6bba59cfd11d34c8f88
URL: https://github.com/llvm/llvm-project/commit/2b3a4c7d72be4fd6792ea6bba59cfd11d34c8f88
DIFF: https://github.com/llvm/llvm-project/commit/2b3a4c7d72be4fd6792ea6bba59cfd11d34c8f88.diff
LOG: [test] Extend negative stride backedge tests to cover signed comparisons
Added:
Modified:
llvm/test/Analysis/ScalarEvolution/trip-count-negative-stride.ll
Removed:
################################################################################
diff --git a/llvm/test/Analysis/ScalarEvolution/trip-count-negative-stride.ll b/llvm/test/Analysis/ScalarEvolution/trip-count-negative-stride.ll
index 6cd2f9fe2807..a013978c84a3 100644
--- a/llvm/test/Analysis/ScalarEvolution/trip-count-negative-stride.ll
+++ b/llvm/test/Analysis/ScalarEvolution/trip-count-negative-stride.ll
@@ -4,9 +4,12 @@
; A collection of tests which exercise SCEV's ability to compute trip counts
; for negative steps.
+; Unsigned Comparisons
+; --------------------
+
; Case where we wrap the induction variable (without generating poison), and
; thus can't currently compute a trip count.
-; CHECK: Determining loop execution counts for: @ult_wrap
+; CHECK-LABEL: Determining loop execution counts for: @ult_wrap
; CHECK: Loop %for.body: Unpredictable backedge-taken count
; CHECK: Loop %for.body: Unpredictable max backedge-taken count
define void @ult_wrap() {
@@ -25,7 +28,7 @@ for.end: ; preds = %for.body, %entry
; This IV cycles between 0, and 128, never causing the loop to exit
; (This is well defined.)
-; CHECK: Determining loop execution counts for: @ult_infinite
+; CHECK-LABEL: Determining loop execution counts for: @ult_infinite
; CHECK: Loop %for.body: Unpredictable backedge-taken count
; CHECK: Loop %for.body: Unpredictable max backedge-taken count
define void @ult_infinite() {
@@ -44,7 +47,7 @@ for.end: ; preds = %for.body, %entry
; Same as ult_infinite, except that the loop is ill defined due to the
; must progress attribute
-; CHECK: Determining loop execution counts for: @ult_infinite_ub
+; CHECK-LABEL: Determining loop execution counts for: @ult_infinite_ub
; CHECK: Loop %for.body: Unpredictable backedge-taken count
; CHECK: Loop %for.body: Unpredictable max backedge-taken count
define void @ult_infinite_ub() mustprogress {
@@ -63,7 +66,7 @@ for.end: ; preds = %for.body, %entry
; Backedge is not taken
-; CHECK: Determining loop execution counts for: @ult_129_not_taken
+; CHECK-LABEL: Determining loop execution counts for: @ult_129_not_taken
; CHECK: Loop %for.body: backedge-taken count is 0
; CHECK: Loop %for.body: max backedge-taken count is 0
@@ -82,7 +85,7 @@ for.end: ; preds = %for.body, %entry
}
; A case with a non-constant stride where the backedge is not taken
-; CHECK: Determining loop execution counts for: @ult_not_taken
+; CHECK-LABEL: Determining loop execution counts for: @ult_not_taken
; CHECK: Loop %for.body: Unpredictable backedge-taken count
; CHECK: Loop %for.body: Unpredictable max backedge-taken count
@@ -106,7 +109,7 @@ for.end: ; preds = %for.body, %entry
; IV does wrap, and thus causes us to branch on poison. This loop is
; ill defined.
-; CHECK: Determining loop execution counts for: @ult_ub1
+; CHECK-LABEL: Determining loop execution counts for: @ult_ub1
; CHECK: Loop %for.body: backedge-taken count is 2
; CHECK: Loop %for.body: max backedge-taken count is 2
@@ -126,7 +129,7 @@ for.end: ; preds = %for.body, %entry
; This loop is ill defined because we violate the nsw flag on the first
; iteration.
-; CHECK: Determining loop execution counts for: @ult_ub2
+; CHECK-LABEL: Determining loop execution counts for: @ult_ub2
; CHECK: Loop %for.body: backedge-taken count is 0
; CHECK: Loop %for.body: max backedge-taken count is 0
@@ -146,7 +149,7 @@ for.end: ; preds = %for.body, %entry
; Large stride, poison produced for %add on second iteration, but not
; branched on.
-; CHECK: Determining loop execution counts for: @ult_129_preinc
+; CHECK-LABEL: Determining loop execution counts for: @ult_129_preinc
; CHECK: Loop %for.body: backedge-taken count is 1
; CHECK: Loop %for.body: max backedge-taken count is 1
@@ -164,7 +167,7 @@ for.end: ; preds = %for.body, %entry
ret void
}
-; CHECK: Determining loop execution counts for: @ult_preinc
+; CHECK-LABEL: Determining loop execution counts for: @ult_preinc
; CHECK: Loop %for.body: backedge-taken count is 1
; CHECK: Loop %for.body: max backedge-taken count is 1
@@ -184,8 +187,189 @@ for.end: ; preds = %for.body, %entry
ret void
}
+; Signed Comparisons
+; ------------------
+
+; Case where we wrap the induction variable (without generating poison), and
+; thus can't currently compute a trip count.
+; CHECK-LABEL: Determining loop execution counts for: @slt_wrap
+; CHECK: Loop %for.body: backedge-taken count is 63
+; CHECK: Loop %for.body: max backedge-taken count is 63
+define void @slt_wrap() {
+entry:
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ 255, %entry ]
+ %add = add i8 %i.05, 254
+ %cmp = icmp slt i8 %add, 127
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+; This IV cycles between 0, and int_min (128), never causing the loop to exit
+; (This is well defined.)
+; CHECK-LABEL: Determining loop execution counts for: @slt_infinite
+; CHECK: Loop %for.body: Unpredictable backedge-taken count
+; CHECK: Loop %for.body: Unpredictable max backedge-taken count
+define void @slt_infinite() {
+entry:
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ 0, %entry ]
+ %add = add i8 %i.05, 128
+ %cmp = icmp slt i8 %add, 127
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+; Same as slt_infinite, except that the loop is ill defined due to the
+; must progress attribute
+; CHECK-LABEL: Determining loop execution counts for: @slt_infinite_ub
+; CHECK: Loop %for.body: Unpredictable backedge-taken count
+; CHECK: Loop %for.body: Unpredictable max backedge-taken count
+define void @slt_infinite_ub() mustprogress {
+entry:
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ 0, %entry ]
+ %add = add i8 %i.05, 128
+ %cmp = icmp slt i8 %add, 127
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+
+; Backedge is not taken
+; CHECK-LABEL: Determining loop execution counts for: @slt_129_not_taken
+; CHECK: Loop %for.body: backedge-taken count is 0
+; CHECK: Loop %for.body: max backedge-taken count is 0
+
+define void @slt_129_not_taken() {
+entry:
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ -128, %entry ]
+ %add = add i8 %i.05, 129
+ %cmp = icmp slt i8 %add, 0
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+; A case with a non-constant stride where the backedge is not taken
+; CHECK-LABEL: Determining loop execution counts for: @slt_not_taken
+; CHECK: Loop %for.body: Unpredictable backedge-taken count
+; CHECK: Loop %for.body: Unpredictable max backedge-taken count
+
+define void @slt_not_taken(i8 %step) {
+entry:
+ %assume = icmp ult i8 128, %step
+ call void @llvm.assume(i1 %assume)
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ -128, %entry ]
+ %add = add i8 %i.05, %step
+ %cmp = icmp slt i8 %add, 0
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+
+
+; IV does wrap, and thus causes us to branch on poison. This loop is
+; ill defined.
+; CHECK-LABEL: Determining loop execution counts for: @slt_ub
+; CHECK: Loop %for.body: backedge-taken count is false
+; CHECK: Loop %for.body: max backedge-taken count is false
+
+define void @slt_ub1() {
+entry:
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ 2, %entry ]
+ %add = add nuw i8 %i.05, 255
+ %cmp = icmp slt i8 %add, 128
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+; This loop is ill defined because we violate the nsw flag on the first
+; iteration.
+; CHECK-LABEL: Determining loop execution counts for: @slt_ub2
+; CHECK: Loop %for.body: backedge-taken count is false
+; CHECK: Loop %for.body: max backedge-taken count is false
+
+define void @slt_ub2() {
+entry:
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ 0, %entry ]
+ %add = add nsw nuw i8 %i.05, 129
+ %cmp = icmp slt i8 %add, 128
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+; Large stride, poison produced for %add on second iteration, but not
+; branched on.
+; CHECK-LABEL: Determining loop execution counts for: @slt_129_preinc
+; CHECK: Loop %for.body: backedge-taken count is 1
+; CHECK: Loop %for.body: max backedge-taken count is 1
+
+define void @slt_129_preinc() {
+entry:
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ -128, %entry ]
+ %add = add nuw i8 %i.05, 129
+ %cmp = icmp slt i8 %i.05, 0
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
+; CHECK-LABEL: Determining loop execution counts for: @slt_preinc
+; CHECK: Loop %for.body: backedge-taken count is 1
+; CHECK: Loop %for.body: max backedge-taken count is 1
+
+define void @slt_preinc(i8 %step) {
+entry:
+ %assume = icmp ult i8 128, %step
+ call void @llvm.assume(i1 %assume)
+ br label %for.body
+
+for.body: ; preds = %entry, %for.body
+ %i.05 = phi i8 [ %add, %for.body ], [ -128, %entry ]
+ %add = add nuw i8 %i.05, 129
+ %cmp = icmp slt i8 %i.05, 0
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end: ; preds = %for.body, %entry
+ ret void
+}
+
declare void @llvm.assume(i1)
-!8 = distinct !{!8, !9}
-!9 = !{!"llvm.loop.mustprogress"}
More information about the llvm-commits
mailing list