[SystemZ] Fold more spills

Add a mapping from register-based <INSN>R instructions to the corresponding
memory-based <INSN>.  Use it to cut down on the number of spill loads.

Some instructions extend their operands from smaller fields, so this
required a new TSFlags field to say how big the unextended operand is.

This optimisation doesn't trigger for C(G)R and CL(G)R because in practice
we always combine those instructions with a branch.  Adding a test for every
other case probably seems excessive, but it did catch a missed optimisation
for DSGF (fixed in r185435).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185529 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Richard Sandiford
2013-07-03 10:10:02 +00:00
parent b81b477cd4
commit fa487e83a8
60 changed files with 4023 additions and 251 deletions

View File

@@ -2,6 +2,8 @@
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
declare i64 @foo()
; Testg register division. The result is in the second of the two registers.
define void @f1(i64 %dummy, i64 %a, i64 %b, i64 *%dest) {
; CHECK: f1:
@@ -152,3 +154,49 @@ define i64 @f12(i64 %dummy, i64 %a, i64 %src, i64 %index) {
%rem = srem i64 %a, %b
ret i64 %rem
}
; Check that divisions of spilled values can use DSG rather than DSGR.
define i64 @f13(i64 *%ptr0) {
; CHECK: f13:
; CHECK: brasl %r14, foo@PLT
; CHECK: dsg {{%r[0-9]+}}, 160(%r15)
; CHECK: br %r14
%ptr1 = getelementptr i64 *%ptr0, i64 2
%ptr2 = getelementptr i64 *%ptr0, i64 4
%ptr3 = getelementptr i64 *%ptr0, i64 6
%ptr4 = getelementptr i64 *%ptr0, i64 8
%ptr5 = getelementptr i64 *%ptr0, i64 10
%ptr6 = getelementptr i64 *%ptr0, i64 12
%ptr7 = getelementptr i64 *%ptr0, i64 14
%ptr8 = getelementptr i64 *%ptr0, i64 16
%ptr9 = getelementptr i64 *%ptr0, i64 18
%ptr10 = getelementptr i64 *%ptr0, i64 20
%val0 = load i64 *%ptr0
%val1 = load i64 *%ptr1
%val2 = load i64 *%ptr2
%val3 = load i64 *%ptr3
%val4 = load i64 *%ptr4
%val5 = load i64 *%ptr5
%val6 = load i64 *%ptr6
%val7 = load i64 *%ptr7
%val8 = load i64 *%ptr8
%val9 = load i64 *%ptr9
%val10 = load i64 *%ptr10
%ret = call i64 @foo()
%div0 = sdiv i64 %ret, %val0
%div1 = sdiv i64 %div0, %val1
%div2 = sdiv i64 %div1, %val2
%div3 = sdiv i64 %div2, %val3
%div4 = sdiv i64 %div3, %val4
%div5 = sdiv i64 %div4, %val5
%div6 = sdiv i64 %div5, %val6
%div7 = sdiv i64 %div6, %val7
%div8 = sdiv i64 %div7, %val8
%div9 = sdiv i64 %div8, %val9
%div10 = sdiv i64 %div9, %val10
ret i64 %div10
}