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Diffstat (limited to 'misc/buildroot/toolchain/gcc/3.4.2/400-mips-pr17565.patch')
| -rw-r--r-- | misc/buildroot/toolchain/gcc/3.4.2/400-mips-pr17565.patch | 102 |
1 files changed, 0 insertions, 102 deletions
diff --git a/misc/buildroot/toolchain/gcc/3.4.2/400-mips-pr17565.patch b/misc/buildroot/toolchain/gcc/3.4.2/400-mips-pr17565.patch deleted file mode 100644 index 7ae6aa56f6..0000000000 --- a/misc/buildroot/toolchain/gcc/3.4.2/400-mips-pr17565.patch +++ /dev/null @@ -1,102 +0,0 @@ -[committed] Fix target/17565: asms in delay slots - - * From: Richard Sandiford <rsandifo at redhat dot com> - * To: gcc-patches at gcc dot gnu dot org - * Date: Mon, 20 Sep 2004 07:55:58 +0100 - * Subject: [committed] Fix target/17565: asms in delay slots - -The MIPS port was allowing asms to be put into delay slots if the -compiler guesses they are only one instruction long. This is wrong -because of the possibility of it containing macros. - -The problem can be reproduced as an assembler warning -in the following testcase: - -int foo (int n) -{ - register int k asm ("$16") = n; - if (k > 0) - { - bar (); - asm ("li %0,0x12345678" : "=r" (k)); - } - return k; -} - -because the multi-instruction asm statement goes into the delay -slot of the call to bar(). - -This is reduced from a much more serious linux problem. Linux is fond -of using empty asm statements, and since gcc estimates empty asms to be -one instruction long, they too might be put into delay slots. This -actually has the effect of putting the following instruction into the -delay slot instead. Since there's no assembler warning, the problem was -only detected as a run-time failure. - -The fix is simple: set the asm value of "can_delay" to "no". -Tested on mipsisa64-elf, applied to mainline. - -This problem goes back to at least 2.95, so it isn't technically a -regression. On the other hand, it's the kind of bug that could trigger -for different types of code in different releases, so I'm sure there's -a testcase that fails (say) in 3.4 and not in 2.95. Will probably ask -Mark for permission to backport to 3.4. - -Richard - - - PR target/17565 - * config/mips/mips.md (define_asm_attributes): Set can_delay to no. - -testsuite/ - * gcc.target/mips/asm-1.c: New test. - -Index: config/mips/mips.md -=================================================================== -RCS file: /cvs/gcc/gcc/gcc/config/mips/mips.md,v -retrieving revision 1.306 -diff -c -p -F^\([(a-zA-Z0-9_]\|#define\) -r1.306 mips.md -*** gcc/gcc/config/mips/mips.md 13 Sep 2004 19:32:05 -0000 1.306 ---- gcc/gcc/config/mips/mips.md 20 Sep 2004 06:52:31 -0000 -*************** (define_attr "may_clobber_hilo" "no,yes" -*** 266,272 **** - - ;; Describe a user's asm statement. - (define_asm_attributes -! [(set_attr "type" "multi")]) - - ;; ......................... - ;; ---- 266,273 ---- - - ;; Describe a user's asm statement. - (define_asm_attributes -! [(set_attr "type" "multi") -! (set_attr "can_delay" "no")]) - - ;; ......................... - ;; -Index: testsuite/gcc.target/mips/asm-1.c -=================================================================== -RCS file: testsuite/gcc.target/mips/asm-1.c -diff -N testsuite/gcc.target/mips/asm-1.c -*** gcc/gcc/testsuite/gcc.target/mips/asm-1.c 1 Jan 1970 00:00:00 -0000 ---- gcc/gcc/testsuite/gcc.target/mips/asm-1.c 20 Sep 2004 06:52:31 -0000 -*************** -*** 0 **** ---- 1,14 ---- -+ /* PR target/17565. GCC used to put the asm into the delay slot -+ of the call. */ -+ /* { dg-do assemble } */ -+ /* { dg-options "-O" } */ -+ int foo (int n) -+ { -+ register int k asm ("$16") = n; -+ if (k > 0) -+ { -+ bar (); -+ asm ("li %0,0x12345678" : "=r" (k)); -+ } -+ return k; -+ } - |