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| author | Niels Möller <nisse@lysator.liu.se> | 2020-12-01 18:47:38 +0100 |
|---|---|---|
| committer | Niels Möller <nisse@lysator.liu.se> | 2020-12-01 18:47:38 +0100 |
| commit | c4ac0953c151dfca6716332247f6aa716ed17b62 (patch) | |
| tree | f2405edeb658ecf9e8adde4e5857de2cad64d033 | |
| parent | 1d2cb8ba6fb85fc0c2653f8a9972c17c6990e23b (diff) | |
| download | nettle-ppc-chacha-4core.tar.gz | |
ppc: Save registers below stack pointer, without modifying it.ppc-chacha-4core
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | powerpc64/p7/chacha-4core.asm | 21 |
2 files changed, 15 insertions, 12 deletions
@@ -1,7 +1,9 @@ 2020-12-01 Niels Möller <nisse@lysator.liu.se> - * powerpc64/p7/chacha-4core.asm (QR): Instruction level - interleaving in the main loop, written by Torbjörn Granlund. + * powerpc64/p7/chacha-4core.asm: Use protected zone below stack + pointer to save registers, without modifying the stack pointer. + (QR): Instruction level interleaving in the main loop, written by + Torbjörn Granlund. 2020-11-30 Niels Möller <nisse@lysator.liu.se> diff --git a/powerpc64/p7/chacha-4core.asm b/powerpc64/p7/chacha-4core.asm index 0cd5c877..b2330247 100644 --- a/powerpc64/p7/chacha-4core.asm +++ b/powerpc64/p7/chacha-4core.asm @@ -132,11 +132,13 @@ PROLOGUE(_nettle_chacha_4core) li r7, 0x20 C ...useful... li r8, 0x30 C ...offsets - addi SP, SP, -0x40 C Save callee-save registers - stvx v20, 0, SP - stvx v21, r6, SP - stvx v22, r7, SP - stvx v23, r8, SP + C Save callee-save registers. Use the "protected zone", max + C 228 bytes, below the stack pointer, accessed via r10. + addi r10, SP, -0x40 + stvx v20, 0, r10 + stvx v21, r6, r10 + stvx v22, r7, r10 + stvx v23, r8, r10 vspltisw ROT16, -16 C -16 instead of 16 actually works! vspltisw ROT12, 12 @@ -257,11 +259,10 @@ IF_BE(` stxvw4x VSR(v15), r8, DST C Restore callee-save registers - lvx v20, 0, SP - lvx v21, r6, SP - lvx v22, r7, SP - lvx v23, r8, SP - addi SP, SP, 0x40 + lvx v20, 0, r10 + lvx v21, r6, r10 + lvx v22, r7, r10 + lvx v23, r8, r10 blr EPILOGUE(_nettle_chacha_4core) |