From 8975f864092f0a1ba561622ba137b305da4a362f Mon Sep 17 00:00:00 2001 From: Ramana Radhakrishnan Date: Tue, 15 Aug 2017 13:58:01 +0100 Subject: [PATCH] [Patch AArch64] Turn lr, fp, ip0 and ip1 into proper aliases We got a report from the linux-arm-kernel folks about getting spurious warnings when building the kernel with binutils 2.29. See https://www.spinics.net/lists/arm-kernel/msg599929.html which boils down to this testcase. $> cat /tmp/tst.s lr .req x30 /tmp/tst.s: Assembler messages: /tmp/tst.s:1: Warning: ignoring attempt to redefine built-in register 'lr' Instead let's treat this as a proper alias at startup time thus avoiding the problem and treating these as proper aliases rather than new registers. This means that attempts to redefine the alias with the same "name" will provoke no warning and attempts to redefine the alias to something else will provoke the above mentioned warning. Tested make check-gas and no regressions. Ok to apply to trunk (and backport to 2.29 branch)? Regards Ramana --- gas/ChangeLog | 10 ++++++++++ gas/config/tc-aarch64.c | 11 ++++++----- gas/doc/c-aarch64.texi | 3 +++ gas/testsuite/gas/aarch64/diagnostic.l | 4 ++++ gas/testsuite/gas/aarch64/diagnostic.s | 5 +++++ gas/testsuite/gas/aarch64/register_aliases.d | 10 ++++++++++ gas/testsuite/gas/aarch64/register_aliases.s | 9 +++++++++ 7 files changed, 47 insertions(+), 5 deletions(-) create mode 100644 gas/testsuite/gas/aarch64/register_aliases.d create mode 100644 gas/testsuite/gas/aarch64/register_aliases.s diff --git a/gas/ChangeLog b/gas/ChangeLog index dd611422313..cdfa036e624 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,13 @@ +2017-08-15 Ramana Radhakrishnan + + * config/tc-aarch64.c (REGDEF_ALIAS): Define + (reg_names): Update for ip0, ip1, fp, lr to use REGDEF_ALIAS + * doc/c-aarch64.texi: Update documentation on .req. + * testsuite/gas/diagnostic.s: Update + * testsuite/gas/diagnostic.l: Likewise + * testsuite/gas/register_aliases.s: New file. + * testsuite/gas/register_aliases.d: New file. + 2017-08-11 H.J. Lu PR gas/21667 diff --git a/gas/config/tc-aarch64.c b/gas/config/tc-aarch64.c index 6a23f21b6c0..0cefa16deba 100644 --- a/gas/config/tc-aarch64.c +++ b/gas/config/tc-aarch64.c @@ -6772,6 +6772,7 @@ aarch64_canonicalize_symbol_name (char *name) also have mixed-case names. */ #define REGDEF(s,n,t) { #s, n, REG_TYPE_##t, TRUE } +#define REGDEF_ALIAS(s, n, t) { #s, n, REG_TYPE_##t, FALSE} #define REGNUM(p,n,t) REGDEF(p##n, n, t) #define REGSET16(p,t) \ REGNUM(p, 0,t), REGNUM(p, 1,t), REGNUM(p, 2,t), REGNUM(p, 3,t), \ @@ -6793,17 +6794,16 @@ static const reg_entry reg_names[] = { REGSET31 (x, R_64), REGSET31 (X, R_64), REGSET31 (w, R_32), REGSET31 (W, R_32), + REGDEF_ALIAS (ip0, 16, R_64), REGDEF_ALIAS (IP0, 16, R_64), + REGDEF_ALIAS (ip1, 17, R_64), REGDEF_ALIAS (IP1, 16, R_64), + REGDEF_ALIAS (fp, 29, R_64), REGDEF_ALIAS (FP, 29, R_64), + REGDEF_ALIAS (lr, 30, R_64), REGDEF_ALIAS (LR, 30, R_64), REGDEF (wsp, 31, SP_32), REGDEF (WSP, 31, SP_32), REGDEF (sp, 31, SP_64), REGDEF (SP, 31, SP_64), REGDEF (wzr, 31, Z_32), REGDEF (WZR, 31, Z_32), REGDEF (xzr, 31, Z_64), REGDEF (XZR, 31, Z_64), - REGDEF (ip0, 16, R_64), REGDEF (IP0, 16, R_64), - REGDEF (ip1, 17, R_64), REGDEF (IP1, 17, R_64), - REGDEF (fp, 29, R_64), REGDEF (FP, 29, R_64), - REGDEF (lr, 30, R_64), REGDEF (LR, 30, R_64), - /* Floating-point single precision registers. */ REGSET (s, FP_S), REGSET (S, FP_S), @@ -6830,6 +6830,7 @@ static const reg_entry reg_names[] = { }; #undef REGDEF +#undef REGDEF_ALIAS #undef REGNUM #undef REGSET16 #undef REGSET31 diff --git a/gas/doc/c-aarch64.texi b/gas/doc/c-aarch64.texi index 677420594e1..e73d48cac24 100644 --- a/gas/doc/c-aarch64.texi +++ b/gas/doc/c-aarch64.texi @@ -363,6 +363,9 @@ example: foo .req w0 @end smallexample +ip0, ip1, lr and fp are automatically defined to +alias to X16, X17, X30 and X29 respectively. + @c SSSSSSSSSSSSSSSSSSSSSSSSSS @c TTTTTTTTTTTTTTTTTTTTTTTTTT diff --git a/gas/testsuite/gas/aarch64/diagnostic.l b/gas/testsuite/gas/aarch64/diagnostic.l index b749d2edfed..cd3ce9931c5 100644 --- a/gas/testsuite/gas/aarch64/diagnostic.l +++ b/gas/testsuite/gas/aarch64/diagnostic.l @@ -172,3 +172,7 @@ [^:]*:295: Error: invalid use of 'MUL' at operand 4 -- `orr x0,x0,#0xff,mul#1' [^:]*:296: Error: invalid use of 'MUL' at operand 4 -- `orr x0,x0,#0xfe,mul#255' [^:]*:297: Error: invalid use of 'MUL' at operand 4 -- `orr x0,x0,#0xfc,mul#256' +[^:]*:299: Warning: ignoring redefinition of register alias 'ip0' +[^:]*:300: Warning: ignoring redefinition of register alias 'ip1' +[^:]*:301: Warning: ignoring redefinition of register alias 'lr' +[^:]*:302: Warning: ignoring redefinition of register alias 'fp' diff --git a/gas/testsuite/gas/aarch64/diagnostic.s b/gas/testsuite/gas/aarch64/diagnostic.s index 09126e623e1..12e85040d36 100644 --- a/gas/testsuite/gas/aarch64/diagnostic.s +++ b/gas/testsuite/gas/aarch64/diagnostic.s @@ -295,3 +295,8 @@ orr x0, x0, #0xff, mul #1 orr x0, x0, #0xfe, mul #255 orr x0, x0, #0xfc, mul #256 + + ip0 .req x0 + ip1 .req x1 + lr .req x2 + fp .req x3 diff --git a/gas/testsuite/gas/aarch64/register_aliases.d b/gas/testsuite/gas/aarch64/register_aliases.d new file mode 100644 index 00000000000..677d5f07523 --- /dev/null +++ b/gas/testsuite/gas/aarch64/register_aliases.d @@ -0,0 +1,10 @@ +#objdump: -dr + +.*: file format .* + +Disassembly of section \.text: + +0+ <.*>: + 0: 8b1e0210 add x16, x16, x30 + 4: f90003b0 str x16, \[x29\] + 8: f94003b1 ldr x17, \[x29\] \ No newline at end of file diff --git a/gas/testsuite/gas/aarch64/register_aliases.s b/gas/testsuite/gas/aarch64/register_aliases.s new file mode 100644 index 00000000000..5864283881c --- /dev/null +++ b/gas/testsuite/gas/aarch64/register_aliases.s @@ -0,0 +1,9 @@ + # test register aliases. + lr .req x30 + fp .req x29 + ip0 .req x16 + ip1 .req x17 + add ip0, ip0, lr + str ip0, [fp] + ldr ip1, [fp] + -- 2.30.2