const CSIVect &CSI) const {
if (shouldInlineCSR(MF, CSI))
return false;
+ // The restore functions do a bit more than just restoring registers.
+ // The non-returning versions will go back directly to the caller's
+ // caller, others will clean up the stack frame in preparation for
+ // a tail call. Using them can still save code size even if only one
+ // register is getting restores. Make the decision based on -Oz:
+ // using -Os will use inline restore for a single register.
+ if (isMinSize(MF))
+ return true;
unsigned NumCSI = CSI.size();
+ if (NumCSI <= 1)
+ return false;
+
unsigned Threshold = isOptSize(MF) ? SpillFuncThresholdOs-1
: SpillFuncThreshold;
return Threshold < NumCSI;
--- /dev/null
+; RUN: llc -march=hexagon < %s | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32:32-a:0-n16:32-i64:64:64-i32:32:32-i16:16:16-i1:8:8-f32:32:32-f64:64:64-v32:32:32-v64:64:64-v512:512:512-v1024:1024:1024-v2048:2048:2048"
+target triple = "hexagon"
+
+; Generate the inline restore for single register pair for functions
+; with "optsize" attribute.
+
+; CHECK-LABEL: fred_os
+; CHECK-DAG: memd{{.*}} = r17:16
+; CHECK-DAG: r17:16 = memd{{.*}}
+; CHECK-DAG: deallocframe
+; CHECK-NOT: call __restore
+
+define i32 @fred_os(i32 %x) #0 {
+entry:
+ %call = tail call i32 @foo(i32 %x) #2
+ %call1 = tail call i32 @bar(i32 %x, i32 %call) #2
+ ret i32 %call1
+}
+
+; Generate the restoring call for single register pair for functions
+; with "minsize" attribute.
+
+; CHECK-LABEL: fred_oz
+; CHECK-DAG: memd{{.*}} = r17:16
+; CHECK-NOT: r17:16 = memd{{.*}}
+; CHECK-DAG: call __restore
+
+define i32 @fred_oz(i32 %x) #1 {
+entry:
+ %call = tail call i32 @foo(i32 %x) #2
+ %call1 = tail call i32 @bar(i32 %x, i32 %call) #2
+ ret i32 %call1
+}
+
+declare i32 @foo(i32) #2
+declare i32 @bar(i32, i32) #2
+
+attributes #0 = { nounwind optsize "disable-tail-calls"="false" }
+attributes #1 = { nounwind minsize "disable-tail-calls"="false" }
+attributes #2 = { nounwind optsize }