[PATCH] D129558: [PPC32] fix stack size allocated for float point argument

[ChenZheng via Phabricator via llvm-commits]

shchenz created this revision.
shchenz added reviewers: nemanjai, jhibbits, kernigh, PowerPC.
Herald added subscribers: kbarton, hiraditya.
Herald added a project: All.
shchenz requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

This is for https://github.com/llvm/llvm-project/issues/56469

For now, we allocate 8 bytes for float type arguments on PPC32. Actually we should use 4 for PPC32. Even though float point value will be converted to double precision when loading and storing, but in the memory, it is still 4 bytes.

I can observe same behavior for PPC32 AIX. Only 4 bytes allocated for float type.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D129558

Files:
  llvm/lib/Target/PowerPC/PPCCallingConv.td
  llvm/test/CodeGen/PowerPC/fminnum.ll
  llvm/test/CodeGen/PowerPC/pr56469.ll


Index: llvm/test/CodeGen/PowerPC/pr56469.ll
===================================================================
--- llvm/test/CodeGen/PowerPC/pr56469.ll
+++ llvm/test/CodeGen/PowerPC/pr56469.ll
@@ -11,11 +11,11 @@
 ; CHECK-NEXT:    stwu 1, -16(1)
 ; CHECK-NEXT:    lfs 1, 24(1)
 ; CHECK-NEXT:    lis 3, .L.str at ha
-; CHECK-NEXT:    lfs 2, 32(1)
+; CHECK-NEXT:    lfs 2, 28(1)
 ; CHECK-NEXT:    la 3, .L.str at l(3)
-; CHECK-NEXT:    lfs 3, 40(1)
+; CHECK-NEXT:    lfs 3, 32(1)
 ; CHECK-NEXT:    creqv 6, 6, 6
-; CHECK-NEXT:    lfs 4, 48(1)
+; CHECK-NEXT:    lfs 4, 36(1)
 ; CHECK-NEXT:    bl printf
 ; CHECK-NEXT:    lwz 0, 20(1)
 ; CHECK-NEXT:    addi 1, 1, 16
Index: llvm/test/CodeGen/PowerPC/fminnum.ll
===================================================================
--- llvm/test/CodeGen/PowerPC/fminnum.ll
+++ llvm/test/CodeGen/PowerPC/fminnum.ll
@@ -328,13 +328,13 @@
 ; CHECK-NEXT:    fmr 30, 7
 ; CHECK-NEXT:    stfd 31, 120(1) # 8-byte Folded Spill
 ; CHECK-NEXT:    fmr 31, 8
-; CHECK-NEXT:    lfs 24, 192(1)
-; CHECK-NEXT:    lfs 23, 184(1)
-; CHECK-NEXT:    lfs 22, 176(1)
-; CHECK-NEXT:    lfs 21, 168(1)
-; CHECK-NEXT:    lfs 20, 160(1)
-; CHECK-NEXT:    lfs 19, 152(1)
-; CHECK-NEXT:    lfs 18, 144(1)
+; CHECK-NEXT:    lfs 24, 164(1)
+; CHECK-NEXT:    lfs 23, 160(1)
+; CHECK-NEXT:    lfs 22, 156(1)
+; CHECK-NEXT:    lfs 21, 152(1)
+; CHECK-NEXT:    lfs 20, 148(1)
+; CHECK-NEXT:    lfs 19, 144(1)
+; CHECK-NEXT:    lfs 18, 140(1)
 ; CHECK-NEXT:    bl fminf
 ; CHECK-NEXT:    fmr 17, 1
 ; CHECK-NEXT:    fmr 1, 25
Index: llvm/lib/Target/PowerPC/PPCCallingConv.td
===================================================================
--- llvm/lib/Target/PowerPC/PPCCallingConv.td
+++ llvm/lib/Target/PowerPC/PPCCallingConv.td
@@ -206,13 +206,8 @@
   
   CCIfType<[i32], CCAssignToStack<4, 4>>,
   
-  // Floats are stored in double precision format, thus they have the same
-  // alignment and size as doubles.
-  // With SPE floats are stored as single precision, so have alignment and
-  // size of int.
-  CCIfType<[f32,f64], CCIfNotSubtarget<"hasSPE()", CCAssignToStack<8, 8>>>,
-  CCIfType<[f32], CCIfSubtarget<"hasSPE()", CCAssignToStack<4, 4>>>,
-  CCIfType<[f64], CCIfSubtarget<"hasSPE()", CCAssignToStack<8, 8>>>,
+  CCIfType<[f32], CCAssignToStack<4, 4>>,
+  CCIfType<[f64], CCAssignToStack<8, 8>>,
 
   // Vectors and float128 get 16-byte stack slots that are 16-byte aligned.
   CCIfType<[v16i8, v8i16, v4i32, v4f32, v2f64, v2i64], CCAssignToStack<16, 16>>,


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D129558.443911.patch
Type: text/x-patch
Size: 2484 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220712/f2439a0a/attachment.bin>