https://github.com/Jade-Marker updated https://github.com/llvm/llvm-project/pull/152942
>From 0f460186012b377067d9e6ac58a2446453f5817b Mon Sep 17 00:00:00 2001 From: Jade Marker <[email protected]> Date: Sun, 10 Aug 2025 22:47:14 +0100 Subject: [PATCH 1/3] Update libunwind::Registers_mips_o32::jumpto to allow for load delay Fix #152922 --- libunwind/src/UnwindRegistersRestore.S | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/libunwind/src/UnwindRegistersRestore.S b/libunwind/src/UnwindRegistersRestore.S index 5e199188945df..346d1d5fb5d8f 100644 --- a/libunwind/src/UnwindRegistersRestore.S +++ b/libunwind/src/UnwindRegistersRestore.S @@ -1044,9 +1044,10 @@ DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind18Registers_mips_o326jumptoEv) lw $27, (4 * 27)($4) lw $28, (4 * 28)($4) lw $29, (4 * 29)($4) - lw $30, (4 * 30)($4) // load new pc into ra lw $31, (4 * 32)($4) + //allow for load delay, so that ra address is new value when jumping + lw $30, (4 * 30)($4) // jump to ra, load a0 in the delay slot jr $31 lw $4, (4 * 4)($4) @@ -1082,11 +1083,13 @@ DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind21Registers_mips_newabi6jumptoEv) ld $2, (8 * 2)($4) ld $3, (8 * 3)($4) // skip a0 for now - .irp i,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30 + .irp i,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29 ld $\i, (8 * \i)($4) .endr // load new pc into ra - ld $31, (8 * 32)($4) + lw $31, (4 * 32)($4) + //allow for load delay, so that ra address is new value when jumping + lw $30, (4 * 30)($4) // jump to ra, load a0 in the delay slot jr $31 ld $4, (8 * 4)($4) >From 9c089f5f227c1fb40486613d77a7b89b89038874 Mon Sep 17 00:00:00 2001 From: Jade Marker <[email protected]> Date: Sun, 10 Aug 2025 22:54:02 +0100 Subject: [PATCH 2/3] Update UnwindRegistersRestore.S Previously, I accidently put lw instead of ld on the mips64 code. Fixed now --- libunwind/src/UnwindRegistersRestore.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libunwind/src/UnwindRegistersRestore.S b/libunwind/src/UnwindRegistersRestore.S index 346d1d5fb5d8f..2b1593b16754e 100644 --- a/libunwind/src/UnwindRegistersRestore.S +++ b/libunwind/src/UnwindRegistersRestore.S @@ -1087,9 +1087,9 @@ DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind21Registers_mips_newabi6jumptoEv) ld $\i, (8 * \i)($4) .endr // load new pc into ra - lw $31, (4 * 32)($4) + ld $31, (4 * 32)($4) //allow for load delay, so that ra address is new value when jumping - lw $30, (4 * 30)($4) + ld $30, (4 * 30)($4) // jump to ra, load a0 in the delay slot jr $31 ld $4, (8 * 4)($4) >From 8273a07fae8e0708b853f7efe1d22a2daa1913bc Mon Sep 17 00:00:00 2001 From: Jade Marker <[email protected]> Date: Wed, 24 Sep 2025 04:24:49 +0100 Subject: [PATCH 3/3] Suggested changes --- libunwind/src/UnwindRegistersRestore.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libunwind/src/UnwindRegistersRestore.S b/libunwind/src/UnwindRegistersRestore.S index 2b1593b16754e..1bcd205be260d 100644 --- a/libunwind/src/UnwindRegistersRestore.S +++ b/libunwind/src/UnwindRegistersRestore.S @@ -1046,7 +1046,7 @@ DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind18Registers_mips_o326jumptoEv) lw $29, (4 * 29)($4) // load new pc into ra lw $31, (4 * 32)($4) - //allow for load delay, so that ra address is new value when jumping + // MIPS 1 has load delay slot. Ensure lw $31 and jr are separated by an instruction. lw $30, (4 * 30)($4) // jump to ra, load a0 in the delay slot jr $31 @@ -1087,9 +1087,9 @@ DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind21Registers_mips_newabi6jumptoEv) ld $\i, (8 * \i)($4) .endr // load new pc into ra - ld $31, (4 * 32)($4) - //allow for load delay, so that ra address is new value when jumping - ld $30, (4 * 30)($4) + ld $31, (8 * 32)($4) + // MIPS 1 has load delay slot. Ensure lw $31 and jr are separated by an instruction. + ld $30, (8 * 30)($4) // jump to ra, load a0 in the delay slot jr $31 ld $4, (8 * 4)($4) _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
