[llvm-branch-commits] [llvm] 967b84c - [AArch64][SVE] Don't support fixedStack for SVE objects.
Hans Wennborg via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Fri Jul 31 08:35:49 PDT 2020
Author: Sander de Smalen
Date: 2020-07-31T17:27:47+02:00
New Revision: 967b84c7a7e2a39d01ab4266bf5eac8c2de98ce5
URL: https://github.com/llvm/llvm-project/commit/967b84c7a7e2a39d01ab4266bf5eac8c2de98ce5
DIFF: https://github.com/llvm/llvm-project/commit/967b84c7a7e2a39d01ab4266bf5eac8c2de98ce5.diff
LOG: [AArch64][SVE] Don't support fixedStack for SVE objects.
Fixed stack objects are preallocated and defined to be allocated before
any of the regular stack objects. These are normally used to model stack
arguments.
The AAPCS does not support passing SVE registers on the stack by value
(only by reference). The current layout also doesn't place them before
all stack objects, but rather before all SVE objects. Removing this
simplifies the code that emits the allocation/deallocation
around callee-saved registers (D84042).
This patch also removes all uses of fixedStack from from
framelayout-sve.mir, where this was used purely for testing purposes.
Reviewers: paulwalker-arm, efriedma, rengolin
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D84538
(cherry picked from commit 54492a5843a34684ce21ae201dd8ca3e509288fd)
Added:
Modified:
llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
llvm/test/CodeGen/AArch64/framelayout-sve.mir
Removed:
################################################################################
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index efa3fd5ca9ce..cc563dd70632 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -2595,20 +2595,21 @@ static int64_t determineSVEStackObjectOffsets(MachineFrameInfo &MFI,
int &MinCSFrameIndex,
int &MaxCSFrameIndex,
bool AssignOffsets) {
+#ifndef NDEBUG
// First process all fixed stack objects.
- int64_t Offset = 0;
for (int I = MFI.getObjectIndexBegin(); I != 0; ++I)
- if (MFI.getStackID(I) == TargetStackID::SVEVector) {
- int64_t FixedOffset = -MFI.getObjectOffset(I);
- if (FixedOffset > Offset)
- Offset = FixedOffset;
- }
+ assert(MFI.getStackID(I) != TargetStackID::SVEVector &&
+ "SVE vectors should never be passed on the stack by value, only by "
+ "reference.");
+#endif
auto Assign = [&MFI](int FI, int64_t Offset) {
LLVM_DEBUG(dbgs() << "alloc FI(" << FI << ") at SP[" << Offset << "]\n");
MFI.setObjectOffset(FI, Offset);
};
+ int64_t Offset = 0;
+
// Then process all callee saved slots.
if (getSVECalleeSaveSlotRange(MFI, MinCSFrameIndex, MaxCSFrameIndex)) {
// Make sure to align the last callee save slot.
diff --git a/llvm/test/CodeGen/AArch64/framelayout-sve.mir b/llvm/test/CodeGen/AArch64/framelayout-sve.mir
index 7903df64863b..575c839fbd15 100644
--- a/llvm/test/CodeGen/AArch64/framelayout-sve.mir
+++ b/llvm/test/CodeGen/AArch64/framelayout-sve.mir
@@ -41,10 +41,10 @@
# +----------+
# |scratchreg| // x29 is used as scratch reg.
# +----------+
-# | %fixed- | // scalable SVE object of n * 18 bytes, aligned to 16 bytes,
-# | stack.0 | // to be materialized with 2*ADDVL (<=> 2 * n * 16bytes)
+# | %stack.0 | // scalable SVE object of n * 18 bytes, aligned to 16 bytes,
+# | | // to be materialized with 2*ADDVL (<=> 2 * n * 16bytes)
# +----------+
-# | %stack.0 | // not scalable
+# | %stack.1 | // not scalable
# +----------+ <- SP
# CHECK-LABEL: name: test_allocate_sve
@@ -60,10 +60,9 @@
# CHECK-NEXT: $sp, $[[SCRATCH]] = frame-destroy LDRXpost $sp, 16
# CHECK-NEXT: RET_ReallyLR
name: test_allocate_sve
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 18, alignment: 2, offset: -18 }
stack:
- - { id: 0, stack-id: default, size: 16, alignment: 8 }
+ - { id: 0, stack-id: sve-vec, size: 18, alignment: 2 }
+ - { id: 1, stack-id: default, size: 16, alignment: 8 }
body: |
bb.0.entry:
RET_ReallyLR
@@ -73,10 +72,9 @@ body: |
# | x20, x21 | // callee saves
# |scratchreg| // x29 is used as scratch reg.
# +----------+
-# | %fixed- | // scalable objects
-# | stack.0 |
+# | %stack.0 | // scalable objects
# +----------+
-# | %stack.0 | // not scalable
+# | %stack.1 | // not scalable
# +----------+ <- SP
# CHECK-LABEL: name: test_allocate_sve_gpr_callee_saves
@@ -95,10 +93,9 @@ body: |
# CHECK-NEXT: $sp, $[[SCRATCH]] = frame-destroy LDRXpost $sp, 32
# CHECK-NEXT: RET_ReallyLR
name: test_allocate_sve_gpr_callee_saves
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 18, alignment: 2, offset: -18 }
stack:
- - { id: 0, stack-id: default, size: 16, alignment: 8 }
+ - { id: 0, stack-id: sve-vec, size: 18, alignment: 2 }
+ - { id: 1, stack-id: default, size: 16, alignment: 8 }
body: |
bb.0.entry:
$x20 = IMPLICIT_DEF
@@ -109,11 +106,10 @@ body: |
# +----------+
# | lr, fp | // frame record
# +----------+ <- FP
-# | %fixed- | // scalable objects
-# | stack.0 |
+# | %stack.0 | // scalable objects
# +----------+
# |//////////| // alignment gap
-# | %stack.0 | // not scalable
+# | %stack.1 | // not scalable
# +----------+ <- SP
# CHECK-LABEL: name: test_allocate_sve_gpr_realigned
# CHECK: stackSize: 32
@@ -128,10 +124,9 @@ body: |
# CHECK-NEXT: $sp, $fp, $lr = frame-destroy LDPXpost $sp, 2
# CHECK-NEXT: RET_ReallyLR
name: test_allocate_sve_gpr_realigned
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 18, alignment: 2, offset: -18 }
stack:
- - { id: 0, stack-id: default, size: 16, alignment: 32 }
+ - { id: 0, stack-id: sve-vec, size: 18, alignment: 2 }
+ - { id: 1, stack-id: default, size: 16, alignment: 32 }
body: |
bb.0.entry:
RET_ReallyLR
@@ -144,7 +139,7 @@ body: |
# | %stack.1 | // scalable @ SP + 16b + 16 scalable bytes
# | %stack.2 | // scalable @ SP + 16b + 14 scalable bytes
# +----------+
-# | %stack.0 | // not scalable
+# | %stack.3 | // not scalable
# +----------+ <- SP
# CHECK-LABEL: name: test_address_sve
@@ -169,19 +164,18 @@ body: |
name: test_address_sve
frameInfo:
maxAlignment: 16
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 16, alignment: 8, offset: -16 }
- - { id: 1, stack-id: sve-vec, size: 16, alignment: 8, offset: -32 }
- - { id: 2, stack-id: sve-vec, size: 2, alignment: 2, offset: -34 }
stack:
- - { id: 0, stack-id: default, size: 16, alignment: 8 }
+ - { id: 0, stack-id: sve-vec, size: 16, alignment: 8 }
+ - { id: 1, stack-id: sve-vec, size: 16, alignment: 8 }
+ - { id: 2, stack-id: sve-vec, size: 2, alignment: 2 }
+ - { id: 3, stack-id: default, size: 16, alignment: 8 }
body: |
bb.0.entry:
liveins: $z0, $z1, $p0
- STR_ZXI $z0, %fixed-stack.0, 0
- STR_ZXI $z1, %fixed-stack.1, 0
- STR_PXI $p0, %fixed-stack.2, 0
+ STR_ZXI $z0, %stack.0, 0
+ STR_ZXI $z1, %stack.1, 0
+ STR_PXI $p0, %stack.2, 0
RET_ReallyLR
---
@@ -190,11 +184,11 @@ body: |
# | x20, x21 | // callee saves
# | lr, fp | // frame record
# +-----------+ <- FP
-# | %fstack.0 | // scalable @ FP - 16 scalable bytes
-# | %fstack.1 | // scalable @ FP - 32 scalable bytes
-# | %fstack.2 | // scalable @ FP - 34 scalable bytes
+# | %stack.0 | // scalable @ FP - 16 scalable bytes
+# | %stack.1 | // scalable @ FP - 32 scalable bytes
+# | %stack.2 | // scalable @ FP - 34 scalable bytes
# +-----------+
-# | %stack.0 | // not scalable
+# | %stack.3 | // not scalable
# +-----------+ <- SP
# CHECK-LABEL: name: test_address_sve_fp
@@ -218,19 +212,18 @@ name: test_address_sve_fp
frameInfo:
maxAlignment: 16
isFrameAddressTaken: true
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 16, alignment: 8, offset: -16 }
- - { id: 1, stack-id: sve-vec, size: 16, alignment: 8, offset: -32 }
- - { id: 2, stack-id: sve-vec, size: 2, alignment: 2, offset: -34 }
stack:
- - { id: 0, stack-id: default, size: 16, alignment: 8 }
+ - { id: 0, stack-id: sve-vec, size: 16, alignment: 8 }
+ - { id: 1, stack-id: sve-vec, size: 16, alignment: 8 }
+ - { id: 2, stack-id: sve-vec, size: 2, alignment: 2 }
+ - { id: 3, stack-id: default, size: 16, alignment: 8 }
body: |
bb.0.entry:
liveins: $z0, $z1, $p0
- STR_ZXI $z0, %fixed-stack.0, 0
- STR_ZXI $z1, %fixed-stack.1, 0
- STR_PXI $p0, %fixed-stack.2, 0
+ STR_ZXI $z0, %stack.0, 0
+ STR_ZXI $z1, %stack.1, 0
+ STR_PXI $p0, %stack.2, 0
RET_ReallyLR
---
@@ -240,9 +233,9 @@ body: |
# +-----------+
# |callee save| // register saved as scratch reg.
# +-----------+
-# | %fstack.1 | // vector of 16 scalable bytes
+# | %stack.0 | // vector of 16 scalable bytes
# +---------- +
-# | %stack.0 | // not scalable, 16 bytes
+# | %stack.1 | // not scalable, 16 bytes
# +-----------+ <- SP
# CHECK-LABEL: name: test_stack_arg_sve
# CHECK: stackSize: 32
@@ -262,9 +255,9 @@ body: |
name: test_stack_arg_sve
fixedStack:
- { id: 0, stack-id: default, size: 16, alignment: 16, offset: 0 }
- - { id: 1, stack-id: sve-vec, size: 16, alignment: 16, offset: -16 }
stack:
- - { id: 0, stack-id: default, size: 16, alignment: 16 }
+ - { id: 0, stack-id: sve-vec, size: 16, alignment: 16 }
+ - { id: 1, stack-id: default, size: 16, alignment: 16 }
body: |
bb.0.entry:
liveins: $x0
@@ -320,17 +313,17 @@ body: |
name: test_address_sve_out_of_range
frameInfo:
maxAlignment: 16
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 16, alignment: 16, offset: -16 }
- - { id: 1, stack-id: sve-vec, size: 3584, alignment: 16, offset: -3600 }
- - { id: 2, stack-id: sve-vec, size: 512, alignment: 16, offset: -4112 }
+stack:
+ - { id: 0, stack-id: sve-vec, size: 16, alignment: 16 }
+ - { id: 1, stack-id: sve-vec, size: 3584, alignment: 16 }
+ - { id: 2, stack-id: sve-vec, size: 512, alignment: 16 }
body: |
bb.0.entry:
liveins: $z0, $p0
- STR_ZXI $z0, %fixed-stack.0, 0
- STR_PXI $p0, %fixed-stack.1, 0
+ STR_ZXI $z0, %stack.0, 0
+ STR_PXI $p0, %stack.1, 0
RET_ReallyLR
---
@@ -340,11 +333,11 @@ body: |
# access from the FP when there are also SVE objects on the stack.
#
# +----------+ <- FP
-# | %fstack.0| // 16 scalable bytes
+# | %stack.0 | // 16 scalable bytes
# +----------+ <- @FP - 16 scalable bytes
-# | %stack.0 | // 16 bytes
+# | %stack.1 | // 16 bytes
# +----------+ <- @BP
-# : %stack.1 : // variable length
+# : %stack.2 : // variable length
# +----------+ <- SP
# CHECK-LABEL: name: test_address_gpr_vla
@@ -354,16 +347,15 @@ body: |
name: test_address_gpr_vla
frameInfo:
maxAlignment: 16
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 16, alignment: 8, offset: -16 }
stack:
- - { id: 0, stack-id: default, size: 16, alignment: 8 }
- - { id: 1, stack-id: default, type: variable-sized }
+ - { id: 0, stack-id: sve-vec, size: 16, alignment: 8 }
+ - { id: 1, stack-id: default, size: 16, alignment: 8 }
+ - { id: 2, stack-id: default, type: variable-sized }
body: |
bb.0.entry:
liveins: $xzr
- STRXui $xzr, %stack.0, 0
+ STRXui $xzr, %stack.1, 0
RET_ReallyLR
---
@@ -429,7 +421,7 @@ body: |
# CHECK-LABEL: name: save_restore_sve
# CHECK: $sp = frame-setup STPXpre killed ${{[a-z0-9]+}}, killed $x21, $sp, -4
# CHECK: frame-setup STPXi killed $x20, killed $x19, $sp, 2
-# CHECK: $sp = frame-setup ADDVL_XXI $sp, -19
+# CHECK: $sp = frame-setup ADDVL_XXI $sp, -18
# CHECK: frame-setup STR_PXI killed $p15, $sp, 4
# CHECK: frame-setup STR_PXI killed $p14, $sp, 5
# CHECK: frame-setup STR_PXI killed $p5, $sp, 14
@@ -438,9 +430,11 @@ body: |
# CHECK: frame-setup STR_ZXI killed $z22, $sp, 3
# CHECK: frame-setup STR_ZXI killed $z9, $sp, 16
# CHECK: frame-setup STR_ZXI killed $z8, $sp, 17
+# CHECK: $sp = frame-setup ADDVL_XXI $sp, -1
# CHECK: $sp = frame-setup SUBXri $sp, 32, 0
# CHECK: $sp = frame-destroy ADDXri $sp, 32, 0
+# CHECK: $sp = frame-destroy ADDVL_XXI $sp, 1
# CHECK: $p15 = frame-destroy LDR_PXI $sp, 4
# CHECK: $p14 = frame-destroy LDR_PXI $sp, 5
# CHECK: $p5 = frame-destroy LDR_PXI $sp, 14
@@ -449,15 +443,14 @@ body: |
# CHECK: $z22 = frame-destroy LDR_ZXI $sp, 3
# CHECK: $z9 = frame-destroy LDR_ZXI $sp, 16
# CHECK: $z8 = frame-destroy LDR_ZXI $sp, 17
-# CHECK: $sp = frame-destroy ADDVL_XXI $sp, 19
+# CHECK: $sp = frame-destroy ADDVL_XXI $sp, 18
# CHECK: $x20, $x19 = frame-destroy LDPXi $sp, 2
# CHECK: $sp, ${{[a-z0-9]+}}, $x21 = frame-destroy LDPXpost $sp, 4
# CHECK: RET_ReallyLR
name: save_restore_sve
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 16, alignment: 16, offset: -16 }
stack:
- - { id: 0, stack-id: default, size: 32, alignment: 16 }
+ - { id: 0, stack-id: sve-vec, size: 16, alignment: 16 }
+ - { id: 1, stack-id: default, size: 32, alignment: 16 }
body: |
bb.0.entry:
@@ -494,7 +487,7 @@ body: |
# CHECK-LABEL: name: save_restore_sve_realign
# CHECK: $sp = frame-setup STPXpre killed $fp, killed $lr, $sp, -2
# CHECK-NEXT: $fp = frame-setup ADDXri $sp, 0, 0
-# CHECK-NEXT: $sp = frame-setup ADDVL_XXI $sp, -19
+# CHECK-NEXT: $sp = frame-setup ADDVL_XXI $sp, -18
# CHECK-NEXT: STR_PXI killed $p15, $sp, 4
# CHECK-NEXT: STR_PXI killed $p14, $sp, 5
# CHECK: STR_PXI killed $p5, $sp, 14
@@ -503,6 +496,7 @@ body: |
# CHECK-NEXT: STR_ZXI killed $z22, $sp, 3
# CHECK: STR_ZXI killed $z9, $sp, 16
# CHECK-NEXT: STR_ZXI killed $z8, $sp, 17
+# CHECK-NEXT: $sp = frame-setup ADDVL_XXI $sp, -1
# CHECK-NEXT: $[[TMP:x[0-9]+]] = frame-setup SUBXri $sp, 16, 0
# CHECK-NEXT: $sp = ANDXri killed $[[TMP]]
@@ -519,10 +513,9 @@ body: |
# CHECK-NEXT: $sp, $fp, $lr = frame-destroy LDPXpost $sp, 2
# CHECK-NEXT: RET_ReallyLR
name: save_restore_sve_realign
-fixedStack:
- - { id: 0, stack-id: sve-vec, size: 16, alignment: 16, offset: -16 }
stack:
- - { id: 0, stack-id: default, size: 16, alignment: 32 }
+ - { id: 0, stack-id: sve-vec, size: 16, alignment: 16 }
+ - { id: 1, stack-id: default, size: 16, alignment: 32 }
body: |
bb.0.entry:
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