[Git][ghc/ghc][master] RTS: Refactor Haskell-C glue for PPC 64-bit
Marge Bot
gitlab at gitlab.haskell.org
Sun Jun 28 13:19:17 UTC 2020
Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC
Commits:
d8ba9e6f by Peter Trommler at 2020-06-28T09:19:11-04:00
RTS: Refactor Haskell-C glue for PPC 64-bit
Make sure the stack is 16 byte aligned even when reserved stack
bytes are not a multiple of 16 bytes.
Avoid saving r2 (TOC). On ELF v1 the function descriptor of StgReturn
has the same TOC as StgRun, on ELF v2 the TOC is recomputed in the
function prologue.
Use the ABI provided functions to save clobbered GPRs and FPRs.
Improve comments. Describe what the stack looks like and how it relates
to the respective ABIs.
- - - - -
2 changed files:
- rts/StgCRun.c
- rts/StgCRunAsm.S
Changes:
=====================================
rts/StgCRun.c
=====================================
@@ -725,17 +725,36 @@ StgRunIsImplementedInAssembler(void)
-------------------------------------------------------------------------- */
#if defined(powerpc64_HOST_ARCH)
-
+/* 64-bit PowerPC ELF ABI 1.9
+ *
+ * Stack frame organization (see Figure 3-17, ELF ABI 1.9, p 14)
+ *
+ * +-> Back Chain (points to the prevoius stack frame)
+ * | Floating point register save area (f14-f31)
+ * | General register save area (r14-r31)
+ * | ... unused save areas (size 0)
+ * | Local variable space
+ * | Parameter save area
+ * | ... stack header (TOC, link editor, compiler, LR, CR)
+ * +-- Back chain <---- SP (r1)
+ *
+ * We save all callee-saves general purpose registers (r14-r31, _savegpr1_14)
+ * and all callee-saves floating point registers (f14-31, _savefpr14) and
+ * the return address of the caller (LR), which is saved in the caller's
+ * stack frame as required by the ABI. We only modify the CR0 and CR1 fields
+ * of the condition register and those are caller-saves, so we don't save CR.
+ *
+ * StgReturn restores all saved registers from their respective locations
+ * on the stack before returning to the caller.
+ *
+ * There is no need to save the TOC register (r2) because we will return
+ * through StgReturn and the calling convention requires that we load
+ * the TOC pointer from the function descriptor upon a call to StgReturn.
+ * That TOC pointer is the same as the TOC pointer in StgRun.
+ */
static void GNUC3_ATTRIBUTE(used)
StgRunIsImplementedInAssembler(void)
{
- // r0 volatile
- // r1 stack pointer
- // r2 toc - needs to be saved
- // r3-r10 argument passing, volatile
- // r11, r12 very volatile (not saved across cross-module calls)
- // r13 thread local state (never modified, don't need to save)
- // r14-r31 callee-save
__asm__ volatile (
".section \".opd\",\"aw\"\n"
".align 3\n"
@@ -743,108 +762,32 @@ StgRunIsImplementedInAssembler(void)
".hidden StgRun\n"
"StgRun:\n"
"\t.quad\t.StgRun,.TOC. at tocbase,0\n"
- "\t.size StgRun,24\n"
+ "\t.size StgRun,.-StgRun\n"
".globl StgReturn\n"
"StgReturn:\n"
"\t.quad\t.StgReturn,.TOC. at tocbase,0\n"
- "\t.size StgReturn,24\n"
+ "\t.size StgReturn,.-StgReturn\n"
".previous\n"
- ".globl .StgRun\n"
- ".type .StgRun, at function\n"
+ ".type StgRun, at function\n"
".StgRun:\n"
"\tmflr 0\n"
- "\tmr 5, 1\n"
- "\tstd 0, 16(1)\n"
+ "\taddi 12,1,-(8*18)\n"
+ "\tbl _savegpr1_14\n"
+ "\tbl _savefpr_14\n"
"\tstdu 1, -%0(1)\n"
- "\tstd 2, -296(5)\n"
- "\tstd 14, -288(5)\n"
- "\tstd 15, -280(5)\n"
- "\tstd 16, -272(5)\n"
- "\tstd 17, -264(5)\n"
- "\tstd 18, -256(5)\n"
- "\tstd 19, -248(5)\n"
- "\tstd 20, -240(5)\n"
- "\tstd 21, -232(5)\n"
- "\tstd 22, -224(5)\n"
- "\tstd 23, -216(5)\n"
- "\tstd 24, -208(5)\n"
- "\tstd 25, -200(5)\n"
- "\tstd 26, -192(5)\n"
- "\tstd 27, -184(5)\n"
- "\tstd 28, -176(5)\n"
- "\tstd 29, -168(5)\n"
- "\tstd 30, -160(5)\n"
- "\tstd 31, -152(5)\n"
- "\tstfd 14, -144(5)\n"
- "\tstfd 15, -136(5)\n"
- "\tstfd 16, -128(5)\n"
- "\tstfd 17, -120(5)\n"
- "\tstfd 18, -112(5)\n"
- "\tstfd 19, -104(5)\n"
- "\tstfd 20, -96(5)\n"
- "\tstfd 21, -88(5)\n"
- "\tstfd 22, -80(5)\n"
- "\tstfd 23, -72(5)\n"
- "\tstfd 24, -64(5)\n"
- "\tstfd 25, -56(5)\n"
- "\tstfd 26, -48(5)\n"
- "\tstfd 27, -40(5)\n"
- "\tstfd 28, -32(5)\n"
- "\tstfd 29, -24(5)\n"
- "\tstfd 30, -16(5)\n"
- "\tstfd 31, -8(5)\n"
"\tmr 27, 4\n" // BaseReg == r27
- "\tld 2, 8(3)\n"
"\tld 3, 0(3)\n"
+ "\tld 2, 8(3)\n"
"\tmtctr 3\n"
"\tbctr\n"
- ".globl .StgReturn\n"
- ".type .StgReturn, at function\n"
+ ".type StgReturn, at function\n"
".StgReturn:\n"
"\tmr 3,14\n"
- "\tla 5, %0(1)\n" // load address == addi r5, r1, %0
- "\tld 2, -296(5)\n"
- "\tld 14, -288(5)\n"
- "\tld 15, -280(5)\n"
- "\tld 16, -272(5)\n"
- "\tld 17, -264(5)\n"
- "\tld 18, -256(5)\n"
- "\tld 19, -248(5)\n"
- "\tld 20, -240(5)\n"
- "\tld 21, -232(5)\n"
- "\tld 22, -224(5)\n"
- "\tld 23, -216(5)\n"
- "\tld 24, -208(5)\n"
- "\tld 25, -200(5)\n"
- "\tld 26, -192(5)\n"
- "\tld 27, -184(5)\n"
- "\tld 28, -176(5)\n"
- "\tld 29, -168(5)\n"
- "\tld 30, -160(5)\n"
- "\tld 31, -152(5)\n"
- "\tlfd 14, -144(5)\n"
- "\tlfd 15, -136(5)\n"
- "\tlfd 16, -128(5)\n"
- "\tlfd 17, -120(5)\n"
- "\tlfd 18, -112(5)\n"
- "\tlfd 19, -104(5)\n"
- "\tlfd 20, -96(5)\n"
- "\tlfd 21, -88(5)\n"
- "\tlfd 22, -80(5)\n"
- "\tlfd 23, -72(5)\n"
- "\tlfd 24, -64(5)\n"
- "\tlfd 25, -56(5)\n"
- "\tlfd 26, -48(5)\n"
- "\tlfd 27, -40(5)\n"
- "\tlfd 28, -32(5)\n"
- "\tlfd 29, -24(5)\n"
- "\tlfd 30, -16(5)\n"
- "\tlfd 31, -8(5)\n"
- "\tmr 1, 5\n"
- "\tld 0, 16(1)\n"
- "\tmtlr 0\n"
- "\tblr\n"
- : : "i"(RESERVED_C_STACK_BYTES+304 /*stack frame size*/));
+ "\tla 1, %0(1)\n" // load address == addi r1, r1, %0
+ "\taddi 12,1,-(8*18)\n"
+ "\tbl _restgpr1_14\n"
+ "\tb _restfpr_14\n"
+ : : "i"((RESERVED_C_STACK_BYTES+288+15) & ~15 /*stack frame size*/));
}
#endif
=====================================
rts/StgCRunAsm.S
=====================================
@@ -7,109 +7,65 @@
#if defined(powerpc64le_HOST_ARCH)
# if defined(linux_HOST_OS)
-# define STACK_FRAME_SIZE RESERVED_C_STACK_BYTES+304
+/* 64-bit PowerPC ELF V2 ABI Revision 1.4
+ *
+ * Stack frame organization (see Figure 2.18, ELF V2 ABI Revision 1.4, p 31)
+ *
+ * +-> Back Chain (points to the prevoius stack frame)
+ * | Floating point register save area (f14-f31)
+ * | General register save area (r14-r31)
+ * | ... unused (optional) save areas (size 0)
+ * | Local variable space
+ * | Parameter save area (8 doublewords)
+ * | ... stack header (TOC, LR, CR)
+ * +-- Back chain <---- SP (r1)
+ *
+ * We save all callee-saves general purpose registers (r14-r31, _savegpr1_14)
+ * and all callee-saves floating point registers (f14-31, _savefpr14) and
+ * the return address of the caller (LR), which is saved in the caller's
+ * stack frame as required by the ABI. We only modify the CR0 and CR1 fields
+ * of the condition register and those are caller-saves, so we don't save CR.
+ *
+ * StgReturn restores all saved registers from their respective locations
+ * on the stack before returning to the caller.
+ *
+ * There is no need to save the TOC register (r2) because we will return
+ * through StgReturn. All calls to StgReturn will be to the global entry
+ * point and we compute the TOC from the entry address of StgReturn, which
+ * is required to be in r12 by the ABI.
+ */
+# define STACK_FRAME_SIZE (RESERVED_C_STACK_BYTES+288+15) & ~15
.file "StgCRun.c"
.abiversion 2
.section ".toc","aw"
.section ".text"
.align 2
-.globl StgRun
-.hidden StgRun
-.type StgRun, at function
+ .globl StgRun
+ .hidden StgRun
+ .type StgRun, at function
StgRun:
-.localentry StgRun,.-StgRun
+ .localentry StgRun,.-StgRun
mflr 0
- mr 5, 1
- std 0, 16(1)
+ addi 12,1,-(8*18)
+ bl _savegpr1_14
+ bl _savefpr_14
stdu 1, -(STACK_FRAME_SIZE)(1)
- std 2, -296(5)
- std 14, -288(5)
- std 15, -280(5)
- std 16, -272(5)
- std 17, -264(5)
- std 18, -256(5)
- std 19, -248(5)
- std 20, -240(5)
- std 21, -232(5)
- std 22, -224(5)
- std 23, -216(5)
- std 24, -208(5)
- std 25, -200(5)
- std 26, -192(5)
- std 27, -184(5)
- std 28, -176(5)
- std 29, -168(5)
- std 30, -160(5)
- std 31, -152(5)
- stfd 14, -144(5)
- stfd 15, -136(5)
- stfd 16, -128(5)
- stfd 17, -120(5)
- stfd 18, -112(5)
- stfd 19, -104(5)
- stfd 20, -96(5)
- stfd 21, -88(5)
- stfd 22, -80(5)
- stfd 23, -72(5)
- stfd 24, -64(5)
- stfd 25, -56(5)
- stfd 26, -48(5)
- stfd 27, -40(5)
- stfd 28, -32(5)
- stfd 29, -24(5)
- stfd 30, -16(5)
- stfd 31, -8(5)
mr 27, 4
mtctr 3
mr 12, 3
bctr
-.globl StgReturn
-.type StgReturn, at function
+
+ .globl StgReturn
+ .type StgReturn, at function
StgReturn:
-.localentry StgReturn,.-StgReturn
+ addis 2,12,.TOC.-StgReturn at ha
+ addi 2,2,.TOC.-StgReturn at l
+ .localentry StgReturn,.-StgReturn
mr 3,14
- la 5, STACK_FRAME_SIZE(1)
- ld 2, -296(5)
- ld 14, -288(5)
- ld 15, -280(5)
- ld 16, -272(5)
- ld 17, -264(5)
- ld 18, -256(5)
- ld 19, -248(5)
- ld 20, -240(5)
- ld 21, -232(5)
- ld 22, -224(5)
- ld 23, -216(5)
- ld 24, -208(5)
- ld 25, -200(5)
- ld 26, -192(5)
- ld 27, -184(5)
- ld 28, -176(5)
- ld 29, -168(5)
- ld 30, -160(5)
- ld 31, -152(5)
- lfd 14, -144(5)
- lfd 15, -136(5)
- lfd 16, -128(5)
- lfd 17, -120(5)
- lfd 18, -112(5)
- lfd 19, -104(5)
- lfd 20, -96(5)
- lfd 21, -88(5)
- lfd 22, -80(5)
- lfd 23, -72(5)
- lfd 24, -64(5)
- lfd 25, -56(5)
- lfd 26, -48(5)
- lfd 27, -40(5)
- lfd 28, -32(5)
- lfd 29, -24(5)
- lfd 30, -16(5)
- lfd 31, -8(5)
- mr 1, 5
- ld 0, 16(1)
- mtlr 0
- blr
+ la 1, STACK_FRAME_SIZE(1)
+ addi 12,1,-(8*18)
+ bl _restgpr1_14
+ b _restfpr_14
.section .note.GNU-stack,"", at progbits
# else // linux_HOST_OS
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d8ba9e6f951a2f8c6e2429a8b2dcb035c392908f
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View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d8ba9e6f951a2f8c6e2429a8b2dcb035c392908f
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