Generalize the cast-of-addrec folding to handle folding of SCEVs like

(sext i8 {-128,+,1} to i64) to i64 {-128,+,1}, where the iteration
crosses from negative to positive, but is still safe if the trip
count is within range.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70421 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 131 insertions, 0 deletions

diff --git a/test/Analysis/ScalarEvolution/sext-iv-0.ll b/test/Analysis/ScalarEvolution/sext-iv-0.ll
new file mode 100644
index 0000000..4b2fcea
--- /dev/null
+++ b/test/Analysis/ScalarEvolution/sext-iv-0.ll
@@ -0,0 +1,31 @@
+; RUN: llvm-as < %s | opt -disable-output -scalar-evolution -analyze \
+; RUN:  | grep { -->  \{-128,+,1\}<bb1>		Exits: 127} | count 5
+
+; Convert (sext {-128,+,1}) to {sext(-128),+,sext(1)}, since the
+; trip count is within range where this is safe.
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @foo(double* nocapture %x) nounwind {
+bb1.thread:
+	br label %bb1
+
+bb1:		; preds = %bb1, %bb1.thread
+	%i.0.reg2mem.0 = phi i64 [ -128, %bb1.thread ], [ %8, %bb1 ]		; <i64> [#uses=3]
+	%0 = trunc i64 %i.0.reg2mem.0 to i8		; <i8> [#uses=1]
+	%1 = trunc i64 %i.0.reg2mem.0 to i9		; <i8> [#uses=1]
+	%2 = sext i9 %1 to i64		; <i64> [#uses=1]
+	%3 = getelementptr double* %x, i64 %2		; <double*> [#uses=1]
+	%4 = load double* %3, align 8		; <double> [#uses=1]
+	%5 = mul double %4, 3.900000e+00		; <double> [#uses=1]
+	%6 = sext i8 %0 to i64		; <i64> [#uses=1]
+	%7 = getelementptr double* %x, i64 %6		; <double*> [#uses=1]
+	store double %5, double* %7, align 8
+	%8 = add i64 %i.0.reg2mem.0, 1		; <i64> [#uses=2]
+	%9 = icmp sgt i64 %8, 127		; <i1> [#uses=1]
+	br i1 %9, label %return, label %bb1
+
+return:		; preds = %bb1
+	ret void
+}
diff --git a/test/Analysis/ScalarEvolution/sext-iv-1.ll b/test/Analysis/ScalarEvolution/sext-iv-1.ll
new file mode 100644
index 0000000..a9175c3
--- /dev/null
+++ b/test/Analysis/ScalarEvolution/sext-iv-1.ll
@@ -0,0 +1,100 @@
+; RUN: llvm-as < %s | opt -disable-output -scalar-evolution -analyze \
+; RUN:  | grep { -->  (sext i. \{.\*,+,.\*\}<bb1> to i64)} | count 5
+
+; Don't convert (sext {...,+,...}) to {sext(...),+,sext(...)} in cases
+; where the trip count is not within range.
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @foo0(double* nocapture %x) nounwind {
+bb1.thread:
+	br label %bb1
+
+bb1:		; preds = %bb1, %bb1.thread
+	%i.0.reg2mem.0 = phi i64 [ -128, %bb1.thread ], [ %8, %bb1 ]		; <i64> [#uses=3]
+	%0 = trunc i64 %i.0.reg2mem.0 to i7		; <i8> [#uses=1]
+	%1 = trunc i64 %i.0.reg2mem.0 to i9		; <i8> [#uses=1]
+	%2 = sext i9 %1 to i64		; <i64> [#uses=1]
+	%3 = getelementptr double* %x, i64 %2		; <double*> [#uses=1]
+	%4 = load double* %3, align 8		; <double> [#uses=1]
+	%5 = mul double %4, 3.900000e+00		; <double> [#uses=1]
+	%6 = sext i7 %0 to i64		; <i64> [#uses=1]
+	%7 = getelementptr double* %x, i64 %6		; <double*> [#uses=1]
+	store double %5, double* %7, align 8
+	%8 = add i64 %i.0.reg2mem.0, 1		; <i64> [#uses=2]
+	%9 = icmp sgt i64 %8, 127		; <i1> [#uses=1]
+	br i1 %9, label %return, label %bb1
+
+return:		; preds = %bb1
+	ret void
+}
+
+define void @foo1(double* nocapture %x) nounwind {
+bb1.thread:
+	br label %bb1
+
+bb1:		; preds = %bb1, %bb1.thread
+	%i.0.reg2mem.0 = phi i64 [ -128, %bb1.thread ], [ %8, %bb1 ]		; <i64> [#uses=3]
+	%0 = trunc i64 %i.0.reg2mem.0 to i8		; <i8> [#uses=1]
+	%1 = trunc i64 %i.0.reg2mem.0 to i9		; <i8> [#uses=1]
+	%2 = sext i9 %1 to i64		; <i64> [#uses=1]
+	%3 = getelementptr double* %x, i64 %2		; <double*> [#uses=1]
+	%4 = load double* %3, align 8		; <double> [#uses=1]
+	%5 = mul double %4, 3.900000e+00		; <double> [#uses=1]
+	%6 = sext i8 %0 to i64		; <i64> [#uses=1]
+	%7 = getelementptr double* %x, i64 %6		; <double*> [#uses=1]
+	store double %5, double* %7, align 8
+	%8 = add i64 %i.0.reg2mem.0, 1		; <i64> [#uses=2]
+	%9 = icmp sgt i64 %8, 128		; <i1> [#uses=1]
+	br i1 %9, label %return, label %bb1
+
+return:		; preds = %bb1
+	ret void
+}
+
+define void @foo2(double* nocapture %x) nounwind {
+bb1.thread:
+	br label %bb1
+
+bb1:		; preds = %bb1, %bb1.thread
+	%i.0.reg2mem.0 = phi i64 [ -129, %bb1.thread ], [ %8, %bb1 ]		; <i64> [#uses=3]
+	%0 = trunc i64 %i.0.reg2mem.0 to i8		; <i8> [#uses=1]
+	%1 = trunc i64 %i.0.reg2mem.0 to i9		; <i8> [#uses=1]
+	%2 = sext i9 %1 to i64		; <i64> [#uses=1]
+	%3 = getelementptr double* %x, i64 %2		; <double*> [#uses=1]
+	%4 = load double* %3, align 8		; <double> [#uses=1]
+	%5 = mul double %4, 3.900000e+00		; <double> [#uses=1]
+	%6 = sext i8 %0 to i64		; <i64> [#uses=1]
+	%7 = getelementptr double* %x, i64 %6		; <double*> [#uses=1]
+	store double %5, double* %7, align 8
+	%8 = add i64 %i.0.reg2mem.0, 1		; <i64> [#uses=2]
+	%9 = icmp sgt i64 %8, 127		; <i1> [#uses=1]
+	br i1 %9, label %return, label %bb1
+
+return:		; preds = %bb1
+	ret void
+}
+
+define void @foo3(double* nocapture %x) nounwind {
+bb1.thread:
+	br label %bb1
+
+bb1:		; preds = %bb1, %bb1.thread
+	%i.0.reg2mem.0 = phi i64 [ -128, %bb1.thread ], [ %8, %bb1 ]		; <i64> [#uses=3]
+	%0 = trunc i64 %i.0.reg2mem.0 to i8		; <i8> [#uses=1]
+	%1 = trunc i64 %i.0.reg2mem.0 to i9		; <i8> [#uses=1]
+	%2 = sext i9 %1 to i64		; <i64> [#uses=1]
+	%3 = getelementptr double* %x, i64 %2		; <double*> [#uses=1]
+	%4 = load double* %3, align 8		; <double> [#uses=1]
+	%5 = mul double %4, 3.900000e+00		; <double> [#uses=1]
+	%6 = sext i8 %0 to i64		; <i64> [#uses=1]
+	%7 = getelementptr double* %x, i64 %6		; <double*> [#uses=1]
+	store double %5, double* %7, align 8
+	%8 = add i64 %i.0.reg2mem.0, -1		; <i64> [#uses=2]
+	%9 = icmp sgt i64 %8, 127		; <i1> [#uses=1]
+	br i1 %9, label %return, label %bb1
+
+return:		; preds = %bb1
+	ret void
+}