[llvm-branch-commits] [llvm] 2812c15 - [PowerPC] Fix missing nop after call to weak callee.
Stefan Pintilie via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Tue Dec 8 07:43:50 PST 2020
Author: Stefan Pintilie
Date: 2020-12-08T09:38:44-06:00
New Revision: 2812c1515627904e31605bbd4f25a887a1f8eb12
URL: https://github.com/llvm/llvm-project/commit/2812c1515627904e31605bbd4f25a887a1f8eb12
DIFF: https://github.com/llvm/llvm-project/commit/2812c1515627904e31605bbd4f25a887a1f8eb12.diff
LOG: [PowerPC] Fix missing nop after call to weak callee.
Weak functions can be replaced by other functions at link time. Previously it
was assumed that no matter what the weak callee function was replaced with it
would still share the same TOC as the caller. This is no longer true as a weak
callee with a TOC setup can be replaced by another function that was compiled
with PC Relative and does not have a TOC at all.
This patch makes sure that all calls to functions defined as weak from a caller
that has a valid TOC have a nop after the call to allow a place for the linker
to restore the TOC.
Reviewed By: NeHuang
Differential Revision: https://reviews.llvm.org/D91983
Added:
Modified:
llvm/lib/Target/PowerPC/PPCISelLowering.cpp
llvm/test/CodeGen/PowerPC/ppc64-blnop.ll
llvm/test/CodeGen/PowerPC/ppc64-calls.ll
llvm/test/CodeGen/PowerPC/ppc64-sibcall.ll
llvm/test/CodeGen/PowerPC/pr41088.ll
llvm/test/CodeGen/PowerPC/preemption.ll
llvm/test/CodeGen/PowerPC/xray-tail-call-hidden.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 90968a3ef8a7..b52054936af0 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -4799,6 +4799,13 @@ static bool callsShareTOCBase(const Function *Caller, SDValue Callee,
if (STICallee->isUsingPCRelativeCalls())
return false;
+ // If the GV is not a strong definition then we need to assume it can be
+ // replaced by another function at link time. The function that replaces
+ // it may not share the same TOC as the caller since the callee may be
+ // replaced by a PC Relative version of the same function.
+ if (!GV->isStrongDefinitionForLinker())
+ return false;
+
// The medium and large code models are expected to provide a sufficiently
// large TOC to provide all data addressing needs of a module with a
// single TOC.
@@ -4806,12 +4813,6 @@ static bool callsShareTOCBase(const Function *Caller, SDValue Callee,
CodeModel::Large == TM.getCodeModel())
return true;
- // Otherwise we need to ensure callee and caller are in the same section,
- // since the linker may allocate multiple TOCs, and we don't know which
- // sections will belong to the same TOC base.
- if (!GV->isStrongDefinitionForLinker())
- return false;
-
// Any explicitly-specified sections and section prefixes must also match.
// Also, if we're using -ffunction-sections, then each function is always in
// a
diff erent section (the same is true for COMDAT functions).
diff --git a/llvm/test/CodeGen/PowerPC/ppc64-blnop.ll b/llvm/test/CodeGen/PowerPC/ppc64-blnop.ll
index 6c3b55d59879..da08390e0748 100644
--- a/llvm/test/CodeGen/PowerPC/ppc64-blnop.ll
+++ b/llvm/test/CodeGen/PowerPC/ppc64-blnop.ll
@@ -76,7 +76,7 @@ define void @wo_hcaller(%class.T* %this, i8* %c) {
; CHECK-LABEL: wo_hcaller:
; CHECK: bl wo_hcallee
-; CHECK-NOT: nop
+; CHECK-NEXT: nop
; SCM-LABEL: wo_hcaller:
; SCM: bl wo_hcallee
@@ -90,7 +90,7 @@ define void @wo_pcaller(%class.T* %this, i8* %c) {
; CHECK-LABEL: wo_pcaller:
; CHECK: bl wo_pcallee
-; CHECK-NOT: nop
+; CHECK-NEXT: nop
; SCM-LABEL: wo_pcaller:
; SCM: bl wo_pcallee
@@ -114,7 +114,7 @@ define void @w_pcaller(i8* %ptr) {
; CHECK-LABEL: w_pcaller:
; CHECK: bl w_pcallee
-; CHECK-NOT: nop
+; CHECK-NEXT: nop
; SCM-LABEL: w_pcaller:
; SCM: bl w_pcallee
@@ -128,7 +128,7 @@ define void @w_hcaller(i8* %ptr) {
; CHECK-LABEL: w_hcaller:
; CHECK: bl w_hcallee
-; CHECK-NOT: nop
+; CHECK-NEXT: nop
; SCM-LABEL: w_hcaller:
; SCM: bl w_hcallee
diff --git a/llvm/test/CodeGen/PowerPC/ppc64-calls.ll b/llvm/test/CodeGen/PowerPC/ppc64-calls.ll
index 245056f7add9..87a746093c45 100644
--- a/llvm/test/CodeGen/PowerPC/ppc64-calls.ll
+++ b/llvm/test/CodeGen/PowerPC/ppc64-calls.ll
@@ -23,18 +23,14 @@ define void @test_direct() nounwind readnone {
ret void
}
-; Calls to weak function requires a TOC restore 'nop' with the small codemodel
+; Calls to weak function requires a TOC restore 'nop' with all code models
; because the definition that gets choosen at link time may come from a
-;
diff erent section even though we have seen a weak definition in the same
-; section at compile time.
-; With large and medium codemodels no TOC restore is needed, since we know
-; whichever definition is choosen it resides within the same DSO boundaries and
-; therefore shares the same TOC.
+;
diff erent compilation unit that was compiled with PC Relative and has no TOC.
define void @test_weak() nounwind readnone {
tail call void @foo_weak() nounwind
; CHECK-LABEL: test_weak:
-; CHECK: b foo_weak
-; CHECK-NOT: nop
+; CHECK: bl foo_weak
+; CHECK-NEXT: nop
; SCM-LABEL: test_weak:
; SCM: bl foo_weak
diff --git a/llvm/test/CodeGen/PowerPC/ppc64-sibcall.ll b/llvm/test/CodeGen/PowerPC/ppc64-sibcall.ll
index 61a588f9bb87..f30bd5435a56 100644
--- a/llvm/test/CodeGen/PowerPC/ppc64-sibcall.ll
+++ b/llvm/test/CodeGen/PowerPC/ppc64-sibcall.ll
@@ -135,7 +135,7 @@ define void @wo_hcaller(%class.T* %this, i8* %c) {
ret void
; CHECK-SCO-LABEL: wo_hcaller:
-; CHECK-SCO: b wo_hcallee
+; CHECK-SCO: bl wo_hcallee
; SCM-LABEL: wo_hcaller:
; SCM: bl wo_hcallee
@@ -147,7 +147,7 @@ define void @wo_pcaller(%class.T* %this, i8* %c) {
ret void
; CHECK-SCO-LABEL: wo_pcaller:
-; CHECK-SCO: b wo_pcallee
+; CHECK-SCO: bl wo_pcallee
; SCM-LABEL: wo_pcaller:
; SCM: bl wo_pcallee
@@ -159,7 +159,7 @@ define void @wo_caller(%class.T* %this, i8* %c) {
ret void
; CHECK-SCO-LABEL: wo_caller:
-; CHECK-SCO: b wo_callee
+; CHECK-SCO: bl wo_callee
; SCM-LABEL: wo_caller:
; SCM: bl wo_callee
@@ -171,7 +171,7 @@ define void @w_pcaller(i8* %ptr) {
ret void
; CHECK-SCO-LABEL: w_pcaller:
-; CHECK-SCO: b w_pcallee
+; CHECK-SCO: bl w_pcallee
; SCM-LABEL: w_pcaller:
; SCM: bl w_pcallee
@@ -183,7 +183,7 @@ define void @w_hcaller(i8* %ptr) {
ret void
; CHECK-SCO-LABEL: w_hcaller:
-; CHECK-SCO: b w_hcallee
+; CHECK-SCO: bl w_hcallee
; SCM-LABEL: w_hcaller:
; SCM: bl w_hcallee
@@ -195,7 +195,7 @@ define void @w_caller(i8* %ptr) {
ret void
; CHECK-SCO-LABEL: w_caller:
-; CHECK-SCO: b w_callee
+; CHECK-SCO: bl w_callee
; SCM-LABEL: w_caller:
; SCM: bl w_callee
diff --git a/llvm/test/CodeGen/PowerPC/pr41088.ll b/llvm/test/CodeGen/PowerPC/pr41088.ll
index 26094358c838..f3899bb15381 100644
--- a/llvm/test/CodeGen/PowerPC/pr41088.ll
+++ b/llvm/test/CodeGen/PowerPC/pr41088.ll
@@ -54,6 +54,7 @@ define void @test(%6* %arg, %7* %arg1, %12* %arg2) unnamed_addr personality i32
; CHECK-NEXT: # %bb.2: # %bb12
; CHECK-NEXT: clrldi r4, r3, 32
; CHECK-NEXT: bl test3
+; CHECK-NEXT: nop
; CHECK-NEXT: addi r1, r1, 32
; CHECK-NEXT: ld r0, 16(r1)
; CHECK-NEXT: mtlr r0
diff --git a/llvm/test/CodeGen/PowerPC/preemption.ll b/llvm/test/CodeGen/PowerPC/preemption.ll
index fc38ba47d8df..849b505b0451 100644
--- a/llvm/test/CodeGen/PowerPC/preemption.ll
+++ b/llvm/test/CodeGen/PowerPC/preemption.ll
@@ -170,7 +170,7 @@ define signext i32 @weak_default_function_caller(i32 %i) {
; STATIC-LABEL: @weak_default_function_caller
; STATIC: bl weak_default_function
-; STATIC-NOT: nop
+; STATIC-NEXT: nop
; STATIC: blr
; CHECK-LABEL: @weak_default_function_caller
@@ -223,12 +223,12 @@ define signext i32 @weak_local_function_caller(i32 %i) {
; STATIC-LABEL: @weak_local_function_caller
; STATIC: bl weak_local_function
-; STATIC-NOT: nop
+; STATIC-NEXT: nop
; STATIC: blr
; CHECK-LABEL: @weak_local_function_caller
; CHECK: bl weak_local_function
-; CHECK-NOT: nop
+; CHECK-NEXT: nop
; CHECK: blr
}
@@ -239,12 +239,12 @@ define i32 @external_local_function_caller(i32 %i) {
; STATIC-LABEL: @external_local_function_caller
; STATIC: bl external_local_function
-; STATIC-NOT: nop
+; STATIC-NEXT: nop
; STATIC: blr
; CHECK-LABEL: @external_local_function_caller
; CHECK: bl external_local_function
-; CHECK-NOT: nop
+; CHECK-NEXT: nop
; CHECK: blr
}
@@ -275,7 +275,7 @@ define signext i32 @weak_preemptable_function_caller(i32 %i) {
; STATIC-LABEL: @weak_preemptable_function_caller
; STATIC: bl weak_preemptable_function
-; STATIC-NOT: nop
+; STATIC-NEXT: nop
; STATIC: blr
; CHECK-LABEL: @weak_preemptable_function_caller
diff --git a/llvm/test/CodeGen/PowerPC/xray-tail-call-hidden.ll b/llvm/test/CodeGen/PowerPC/xray-tail-call-hidden.ll
index 3b1cd5f5870d..d427dbb4238e 100644
--- a/llvm/test/CodeGen/PowerPC/xray-tail-call-hidden.ll
+++ b/llvm/test/CodeGen/PowerPC/xray-tail-call-hidden.ll
@@ -12,12 +12,12 @@ define i32 @caller() nounwind noinline uwtable "function-instrument"="xray-alway
; CHECK-NEXT: nop
; CHECK-NEXT: mtlr 0
; CHECK-LABEL: .Ltmp1:
+; CHECK: bl callee
+; CHECK-NEXT: nop
%retval = tail call i32 @callee()
ret i32 %retval
; CHECK-LABEL: .Ltmp2:
-; CHECK: b callee
-; CHECK-NEXT: nop
-; CHECK-NEXT: std 0, -8(1)
+; CHECK: std 0, -8(1)
; CHECK-NEXT: mflr 0
; CHECK-NEXT: bl __xray_FunctionExit
; CHECK-NEXT: nop
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